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Lucas pseudoprime

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7594: 1065:
323, 35, 119, 9, 9, 143, 25, 33, 9, 15, 123, 35, 9, 9, 15, 129, 51, 9, 33, 15, 21, 9, 9, 49, 15, 39, 9, 35, 49, 15, 9, 9, 33, 51, 15, 9, 35, 85, 39, 9, 9, 21, 25, 51, 9, 143, 33, 119, 9, 9, 51, 33, 95, 9, 15, 301, 25, 9, 9, 15, 49, 155, 9, 399, 15, 33, 9, 9, 49, 15, 119, 9,
4297: 1750: 4913: 2096: 4102: 2695: 255: 4694:
pseudoprimes. Hoggatt and Bicknell studied properties of these pseudoprimes in 1974. Singmaster computed these pseudoprimes up to 100000. Jacobsen lists all 111443 of these pseudoprimes less than 10.
1131: 2885: 890: 1818: 1323: 336: 2790: 559: 3589: 3492: 2025: 1956: 945: 4624: 2147: 818: 1905:, the number to be tested for primality, is odd, is not a perfect square, and is not divisible by any small prime less than some convenient limit. Perfect squares are easy to detect using 1000: 4143: 3786: 3655: 499: 187: 628: 1255: 2582: 2999: 2941: 3673:
Although this congruence condition is not, by definition, part of the Lucas probable prime test, it is almost free to check this condition because, as noted above, the value of
5696: 4168: 1859: 2397: 1539: 1164: 4002: 3866: 3446: 109: 2477: 2231: 3035: 1427: 3935: 3902: 2437: 2355: 2322: 1891: 1620: 1593: 3400: 2185: 2523: 3955: 3323:
are chosen as described above, the first 10 Lucas pseudoprimes are (see page 1401 of ): 323, 377, 1159, 1829, 3827, 5459, 5777, 9071, 9179, and 10877 (sequence
3121: 3101: 3081: 2500: 1559: 1507: 1487: 1467: 1447: 1391: 1371: 1184: 509:. Typically implementations will use a parameter selection method that ensures this condition (e.g. the Selfridge method recommended in and described below). 1666: 4833: 4704: 4683: 4517: 3517: 3366: 3330: 740: 5689: 4847: 4697:
It has been shown that there are no even Fibonacci pseudoprimes as defined by equation (5). However, even Fibonacci pseudoprimes do exist (sequence
2030: 4539:
is congruent to 1 or 4 modulo 5, the opposite is true, with over 12% of Fibonacci pseudoprimes under 10 also being base-2 Fermat pseudoprimes.
4021: 2588: 4531:
is congruent to 2 or 3 modulo 5, then Bressoud, and Crandall and Pomerance point out that it is rare for a Fibonacci pseudoprime to also be a
5075: 501:
is −1 (see pages 1401–1409 of, page 1024 of, or pages 266–269 of ). This is especially important when combining a Lucas test with a
4330: 6496: 5682: 5553:
MĂŒller, Winfried B.; Oswald, Alan (1993). "Generalized Fibonacci Pseudoprimes and Probable Primes". In G.E. Bergum; et al. (eds.).
6491: 6506: 6486: 3146:+1 = 44 (= 101100 in binary), then, taking the bits one at a time from left to right, we obtain the sequence of indices to compute: 1 5153: 5116: 4315:
The Jacobi symbol on the right side is easy to compute, so this congruence is easy to check. If this congruence does not hold, then
1353:
There are infinitely many strong Lucas pseudoprimes, and therefore, infinitely many Lucas pseudoprimes. Theorem 7 in states: Let
7199: 6779: 2157:
values that must be tried before we encounter one whose Jacobi symbol is −1 is about 1.79; see, p. 1416. Once we have
4360: 199: 1078: 4447: 2796: 506: 6501: 7285: 837: 699:
is prime. As is the case with any other probabilistic primality test, if we perform additional Lucas tests with different
395:. Hence, every Frobenius pseudoprime is also a Baillie-Wagstaff-Lucas pseudoprime, but the converse does not always hold. 6601: 3534:) is true, there are additional congruence conditions we can check that have almost no additional computational cost. If 1761: 1266: 6951: 6270: 6063: 4948:) = (2, −1), leading to the pseudoprimes 169, 385, 961, 1105, 1121, 3827, 4901, 6265, 6441, 6601, 7107, 7801, 8119, ... 280: 6986: 6956: 6631: 6621: 2707: 7127: 6541: 6275: 6255: 515: 6817: 3548: 3451: 1984: 1915: 913: 6981: 4562: 2109: 786: 7618: 7076: 6699: 6456: 6265: 6247: 6141: 6131: 6121: 5595:(data for Lucas, Strong Lucas, AES Lucas, ES Lucas pseudoprimes below 10; Fibonacci and Pell pseudoprimes below 10) 953: 6961: 4111: 3754: 3599: 467: 155: 7204: 6749: 6370: 6156: 6151: 6146: 6136: 6113: 575: 6189: 3818:) is true (see page 1409 and Table 6 of;). More extensive calculations show that, with this method of choosing 6446: 1211: 2531: 7315: 7280: 7066: 6976: 6850: 6825: 6734: 6724: 6336: 6318: 6238: 5424: 5284: 5177: 4993: 2946: 3868:, then a further congruence condition that involves very little additional computation can be implemented. 7575: 6845: 6719: 6350: 6126: 5906: 5833: 5530: 5404: 5395:
Di Porto, Adina; Filipponi, Piero; Montolivo, Emilio (1990). "On the generalized Fibonacci pseudoprimes".
5341: 4292:{\displaystyle Q^{(n+1)/2}\equiv Q\cdot Q^{(n-1)/2}\equiv Q\cdot \left({\tfrac {Q}{n}}\right){\pmod {n}}.} 2894: 3359:
Lucas pseudoprimes are: 5459, 5777, 10877, 16109, 18971, 22499, 24569, 25199, 40309, and 58519 (sequence
7623: 6830: 6684: 6611: 5766: 4443: 392: 7539: 7179: 4787:
The smallest example of a strong Fibonacci pseudoprime is 443372888629441 = 17·31·41·43·89·97·167·331.
3510:
Lucas pseudoprimes are 989, 3239, 5777, 10877, 27971, 29681, 30739, 31631, 39059, and 72389 (sequence
402:
code), pages 142–152 of the book by Crandall and Pomerance, and pages 53–74 of the book by Ribenboim.
7472: 7366: 7330: 7071: 6794: 6774: 6591: 6260: 6048: 6020: 5247: 4012: 5535: 5427:; Marjorie Bicknell (September 1974). "Some Congruences of the Fibonacci Numbers Modulo a Prime p". 5409: 5346: 1826: 7194: 7058: 7053: 7021: 6784: 6759: 6754: 6729: 6659: 6655: 6586: 6476: 6308: 6104: 6073: 2360: 1512: 7593: 1136: 7597: 7351: 7346: 7260: 7234: 7132: 7111: 6883: 6764: 6714: 6636: 6606: 6546: 6313: 6293: 6224: 5937: 5660: 5444: 5314: 5296: 5237: 5206: 5022: 4532: 3960: 3842: 3042: 502: 6481: 4436: 3409: 1906: 72: 2443: 2190: 7491: 7436: 7290: 7265: 7239: 7016: 6694: 6689: 6596: 6581: 6303: 6285: 6204: 6194: 6179: 5957: 5942: 5657: 5638: 5619: 5600: 5173: 5149: 5112: 5071: 4937:. The first pseudoprimes are then 169, 385, 741, 961, 1121, 2001, 3827, 4879, 5719, 6215 ... 4750: 4446:, say, to base 2, one can obtain very powerful probabilistic tests for primality, such as the 3004: 1396: 3907: 3874: 2409: 2327: 2294: 7527: 7320: 6906: 6878: 6868: 6860: 6744: 6709: 6704: 6671: 6365: 6328: 6219: 6214: 6209: 6199: 6171: 6058: 6010: 6005: 5962: 5901: 5641: 5580: 5558: 5436: 5351: 5306: 5255: 5196: 5096: 5012: 38: 5269: 5034: 1864: 1598: 1571: 7503: 7392: 7325: 7251: 7174: 7148: 6966: 6679: 6536: 6471: 6441: 6431: 6426: 6092: 6000: 5947: 5791: 5731: 5603: 5265: 5145: 5137: 5108: 5030: 4146: 1336:; see page 1396 of. A strong Lucas pseudoprime is also a Lucas pseudoprime (for the same ( 5521:
Di Porto, Adina (1993). "Nonexistence of Even Fibonacci Pseudoprimes of the First Kind".
3379: 2164: 5251: 2505: 7508: 7376: 7361: 7225: 7189: 7164: 7040: 7011: 6996: 6873: 6769: 6739: 6466: 6421: 6298: 5896: 5891: 5886: 5858: 5843: 5756: 5741: 5719: 5706: 5586: 5169: 5100: 5064: 5055: 3940: 3797: 3106: 3086: 3066: 2485: 2400: 2258: 1544: 1492: 1472: 1452: 1432: 1376: 1356: 1169: 379: 142: 46: 5622: 5201: 5017: 4828:. The first pseudoprimes are then 35, 169, 385, 779, 899, 961, 1121, 1189, 2419, ... 7612: 7431: 7415: 7356: 7310: 7006: 6991: 6901: 6626: 6184: 6053: 6015: 5972: 5853: 5838: 5828: 5786: 5776: 5751: 5318: 4934: 4825: 190: 17: 1861:. An extra strong Lucas pseudoprime is also a strong Lucas pseudoprime for the same 1745:{\displaystyle U_{d}\equiv 0{\pmod {n}}{\text{ and }}V_{d}\equiv \pm 2{\pmod {n}}} 7467: 7456: 7371: 7209: 7184: 7101: 7001: 6971: 6946: 6930: 6835: 6802: 6551: 6525: 6436: 6375: 5952: 5848: 5781: 5761: 5736: 265: 42: 5355: 5260: 5225: 4370:
There is a similar probability estimate for the strong Lucas probable prime test.
3538:
happens to be composite, these additional conditions may help discover that fact.
5562: 7426: 7301: 7106: 6570: 6461: 6416: 6411: 6161: 6068: 5967: 5796: 5771: 5746: 3830:, there are only five odd, composite numbers less than 10 for which congruence ( 399: 7563: 7544: 6840: 6451: 5181: 5059: 4908:{\displaystyle {\text{ }}U_{n}\equiv \left({\tfrac {2}{n}}\right){\pmod {n}}} 4420: 5674: 45:
and very few composite numbers pass: in this case, criteria relative to some
7169: 7096: 7088: 6893: 6807: 5925: 5665: 5646: 5627: 5608: 5332:
F. Arnault (April 1997). "The Rabin-Monier Theorem for Lucas Pseudoprimes".
4997: 4676:
705, 2465, 2737, 3745, 4181, 5777, 6721, 10877, 13201, 15251, ... (sequence
4506:= −1. By this definition, the Fibonacci pseudoprimes form a sequence: 2091:{\displaystyle \left({\tfrac {k}{n}}\right)\left({\tfrac {-k}{n}}\right)=-1} 3056:
sequence. As we proceed, we also compute the same, corresponding powers of
398:
Some good references are chapter 8 of the book by Bressoud and Wagon (with
378:
does not hold. These are the key facts that make Lucas sequences useful in
57:
Baillie and Wagstaff define Lucas pseudoprimes as follows: Given integers
7270: 5370: 4510:
323, 377, 1891, 3827, 4181, 5777, 6601, 6721, 8149, 10877, ... (sequence
4097:{\displaystyle Q^{(n-1)/2}\equiv \left({\tfrac {Q}{n}}\right){\pmod {n}}} 2690:{\displaystyle V_{2k}=V_{k}^{2}-2Q^{k}={\frac {V_{k}^{2}+DU_{k}^{2}}{2}}} 5310: 2276:
for squareness until after the first few search steps have all failed.)
7275: 6934: 5592: 5481: 5448: 5210: 5026: 4435:+1) is a perfect square. One can quickly detect perfect squares using 1901:
Before embarking on a probable prime test, one usually verifies that
5440: 5301: 5242: 4524:
The references of Anderson and Jacobsen below use this definition.
2291:, there are recurrence relations that enable us to quickly compute 4672:
This definition leads the Fibonacci pseudoprimes form a sequence:
4642:
This leads to an alternative definition of Fibonacci pseudoprime:
1489:) such that the number of strong Lucas pseudoprimes not exceeding 1340:) pair), but the converse is not necessarily true. Therefore, the 5070:. New York: Key College Publishing in cooperation with Springer. 3591:, then we have the following (see equation 2 on page 1392 of ): 2272:
is not square. Thus, some time can be saved by delaying testing
2268:
is square, and conversely if it does succeed, that is proof that
4396:
applications of the strong Lucas test would declare a composite
4373:
Aside from two trivial exceptions (see below), the fraction of (
3710:
of these congruences are true, then it is even more likely that
3340:
versions of the Lucas test can be implemented in a similar way.
1429:
is positive but not a square. Then there is a positive constant
7561: 7525: 7489: 7453: 7413: 7038: 6927: 6653: 6568: 6523: 6400: 6090: 6037: 5989: 5923: 5875: 5813: 5717: 5678: 3001:; this is even so it can now be divided by 2. The numerator of 2701:
Next, we can increase the subscript by 1 using the recurrences
5581:
Fibonacci Pseudoprimes, their factors, and their entry points.
5587:
Fibonacci Pseudoprimes under 2,217,967,487 and their factors.
5287:(July 2021). "Strengthening the Baillie-PSW Primality Test". 4329:) is equivalent to augmenting our Lucas test with a "base Q" 1025: 4344:
of these conditions fails to hold, then we have proved that
4837: 4699: 4678: 4512: 4336:
Additional congruence conditions that must be satisfied if
3512: 3361: 3325: 744: 3937:, and we can easily save the previously computed power of 250:{\displaystyle \delta (n)=n-\left({\tfrac {D}{n}}\right).} 1126:{\displaystyle \delta (n)=n-\left({\tfrac {D}{n}}\right)} 4400:
to be probably prime with a probability at most (4/15).
2880:{\displaystyle V_{2k+1}=(D\cdot U_{2k}+P\cdot V_{2k})/2} 4367:
to be probably prime with a probability at most (1/4).
1648:
is a strong Lucas pseudoprime for a set of parameters (
1637:, for example, the least strong Lucas pseudoprime with 1344:
test is a more stringent primality test than equation (
4874: 4255: 4120: 4063: 3763: 3557: 3460: 3048:.) Observe that, for each term that we compute in the 2118: 2059: 2039: 1993: 1924: 1108: 922: 885:{\displaystyle U_{20}=6616217487\equiv 0{\pmod {19}}.} 795: 673:
is prime or it is a Lucas pseudoprime. If congruence (
524: 476: 229: 164: 5502:
P. S. Bruckman (1994). "Lucas Pseudoprimes are odd".
4850: 4565: 4171: 4114: 4024: 3963: 3943: 3910: 3877: 3845: 3757: 3602: 3551: 3454: 3412: 3382: 3273:
By the end of the calculation, we will have computed
3109: 3089: 3069: 3007: 2949: 2897: 2799: 2710: 2591: 2534: 2508: 2488: 2446: 2412: 2363: 2330: 2297: 2193: 2167: 2112: 2033: 1987: 1918: 1867: 1829: 1764: 1669: 1601: 1574: 1547: 1515: 1495: 1475: 1455: 1435: 1399: 1379: 1359: 1269: 1214: 1172: 1139: 1081: 1013:) pair. In fact, 119 is the smallest pseudoprime for 956: 916: 840: 789: 578: 518: 470: 283: 202: 158: 75: 5462:
David Singmaster (1983). "Some Lucas Pseudoprimes".
1005:
However, 119 = 7·17 is not prime, so 119 is a Lucas
7385: 7339: 7299: 7250: 7224: 7157: 7141: 7120: 7087: 7052: 6892: 6859: 6816: 6793: 6670: 6358: 6349: 6327: 6284: 6246: 6237: 6170: 6112: 6103: 5091: 5089: 5087: 3052:sequence, we compute the corresponding term in the 1912:We choose a Lucas sequence where the Jacobi symbol 1813:{\displaystyle V_{d\cdot 2^{r}}\equiv 0{\pmod {n}}} 1318:{\displaystyle V_{d\cdot 2^{r}}\equiv 0{\pmod {n}}} 5063: 4907: 4742:is a strong Fibonacci pseudoprime if and only if: 4618: 4291: 4153:is prime, this is the same as the Jacobi symbol). 4137: 4096: 3996: 3949: 3929: 3896: 3860: 3780: 3649: 3583: 3486: 3440: 3394: 3115: 3095: 3075: 3029: 2993: 2935: 2879: 2784: 2689: 2576: 2517: 2494: 2471: 2431: 2391: 2349: 2316: 2225: 2179: 2141: 2090: 2019: 1950: 1885: 1853: 1812: 1744: 1614: 1587: 1553: 1533: 1501: 1481: 1461: 1441: 1421: 1385: 1365: 1317: 1249: 1178: 1158: 1125: 994: 939: 895:Therefore, 19 is a Lucas probable prime for this ( 884: 812: 622: 553: 493: 331:{\displaystyle U_{\delta (n)}\equiv 0{\pmod {n}}.} 330: 249: 181: 103: 27:Probabilistic test for the primality of an integer 3714:is prime than if we had checked only congruence ( 3234:. We also compute the same-numbered terms in the 2785:{\displaystyle U_{2k+1}=(P\cdot U_{2k}+V_{2k})/2} 272:, then the following congruence condition holds: 1630:-Lucas sequence, the pseudoprimes can be called 1393:be relatively prime positive integers for which 669:is a Lucas probable prime. In this case, either 554:{\displaystyle \left({\tfrac {D}{n}}\right)=-1,} 4352:Comparison with the Miller–Rabin primality test 3800:). If we use this enhanced method for choosing 3584:{\displaystyle \left({\tfrac {D}{n}}\right)=-1} 3487:{\displaystyle \left({\tfrac {D}{n}}\right)=-1} 2020:{\displaystyle \left({\tfrac {D}{n}}\right)=-1} 1951:{\displaystyle \left({\tfrac {D}{n}}\right)=-1} 940:{\displaystyle \left({\tfrac {13}{119}}\right)} 391:) represents one of two congruences defining a 4619:{\displaystyle V_{n}(P,Q)\equiv P{\pmod {n}}.} 2142:{\displaystyle \left({\tfrac {D}{n}}\right)=0} 813:{\displaystyle \left({\tfrac {13}{19}}\right)} 460:A Lucas probable prime test is most useful if 5690: 4481:) sequence represents the Fibonacci numbers. 4442:By combining a Lucas pseudoprime test with a 3812:composite less than 10 for which congruence ( 1981:in the sequence 5, −7, 9, −11, ... such that 995:{\displaystyle U_{120}\equiv 0{\pmod {119}}.} 8: 4738:. It follows that an odd composite integer 4138:{\displaystyle \left({\tfrac {Q}{n}}\right)} 3781:{\displaystyle \left({\tfrac {D}{n}}\right)} 3723:If Selfridge's method (above) for choosing 3650:{\displaystyle V_{n+1}\equiv 2Q{\pmod {n}}.} 3355:are chosen as described above, the first 10 3130:We use the bits of the binary expansion of 1977:is to use trial and error to find the first 494:{\displaystyle \left({\tfrac {D}{n}}\right)} 182:{\displaystyle \left({\tfrac {D}{n}}\right)} 5132: 5130: 5128: 4940:A third definition uses equation (5) with ( 4340:is prime are described in Section 6 of. If 2525:in one step using the recurrence relations 899:) pair. In this case 19 is prime, so it is 715:is composite, we gain more confidence that 711:, then unless one of the tests proves that 623:{\displaystyle U_{n+1}\equiv 0{\pmod {n}}.} 41:integers that pass certain tests which all 7558: 7522: 7486: 7450: 7410: 7084: 7049: 7035: 6924: 6667: 6650: 6565: 6520: 6397: 6355: 6243: 6109: 6100: 6087: 6034: 5991:Possessing a specific set of other numbers 5986: 5920: 5872: 5810: 5714: 5697: 5683: 5675: 5105:Prime numbers: A computational perspective 5050: 5048: 5046: 5044: 3702:) is false, this constitutes a proof that 652:) is false, this constitutes a proof that 5557:. Vol. 5. Kluwer. pp. 459–464. 5548: 5546: 5534: 5408: 5345: 5300: 5259: 5241: 5200: 5016: 4889: 4873: 4860: 4851: 4849: 4597: 4570: 4564: 4492:not divisible by 5 for which congruence ( 4427:is easy to factor, because in this case, 4403:There are two trivial exceptions. One is 4270: 4254: 4231: 4215: 4192: 4176: 4170: 4119: 4113: 4078: 4062: 4045: 4029: 4023: 3984: 3968: 3962: 3942: 3915: 3909: 3882: 3876: 3844: 3762: 3756: 3680:was computed in the process of computing 3628: 3607: 3601: 3556: 3550: 3524:Checking additional congruence conditions 3459: 3453: 3423: 3411: 3381: 3108: 3088: 3068: 3012: 3006: 2976: 2960: 2948: 2924: 2908: 2896: 2869: 2857: 2835: 2804: 2798: 2774: 2762: 2746: 2715: 2709: 2675: 2670: 2654: 2649: 2642: 2633: 2617: 2612: 2596: 2590: 2568: 2555: 2539: 2533: 2507: 2487: 2451: 2445: 2417: 2411: 2374: 2362: 2335: 2329: 2302: 2296: 2215: 2192: 2166: 2117: 2111: 2058: 2038: 2032: 1992: 1986: 1923: 1917: 1866: 1828: 1794: 1780: 1769: 1763: 1726: 1711: 1702: 1686: 1674: 1668: 1606: 1600: 1579: 1573: 1546: 1514: 1494: 1474: 1454: 1434: 1404: 1398: 1378: 1358: 1299: 1285: 1274: 1268: 1231: 1219: 1213: 1171: 1150: 1138: 1107: 1080: 973: 961: 955: 921: 915: 863: 845: 839: 794: 788: 601: 583: 577: 523: 517: 475: 469: 309: 288: 282: 228: 201: 163: 157: 86: 74: 5593:Pseudoprime Statistics, Tables, and Data 5369:Adina Di Porto; Piero Filipponi (1989). 4389:to be probably prime is at most (4/15). 2482:First, we can double the subscript from 1897:Implementing a Lucas probable prime test 1250:{\displaystyle U_{d}\equiv 0{\pmod {n}}} 1205:) = 1, satisfying one of the conditions 1057:= −1, the smallest Lucas pseudoprime to 831:= 6616217487 = 19·348221973 and we have 5066:A Course in Computational Number Theory 4987: 4985: 4983: 4981: 4957: 4707:) under the first definition given by ( 4488:is often defined as a composite number 2577:{\displaystyle U_{2k}=U_{k}\cdot V_{k}} 1641:= 1, 2, 3, ... are 4181, 169, 119, ... 4979: 4977: 4975: 4973: 4971: 4969: 4967: 4965: 4963: 4961: 3904:is computed during the calculation of 2994:{\displaystyle P\cdot U_{2k}+V_{2k}+n} 1660:= 1, satisfying one of the conditions 464:is chosen such that the Jacobi symbol 406:Lucas probable primes and pseudoprimes 4799:may be defined as a composite number 3142:sequence to compute. For example, if 2401:Lucas sequence § Other relations 687:to be prime (this justifies the term 7: 5371:"More on the Fibonacci Pseudoprimes" 5142:The New Book of Prime Number Records 4831:This differs from the definition in 4556: 4162: 3593: 3528:If we have checked that congruence ( 3406:= 3, 4, 5, 6, ..., until a value of 3037:is handled in the same way. (Adding 2936:{\displaystyle P\cdot U_{2k}+V_{2k}} 2237:has no prime factors in common with 2106:have a prime factor in common, then 569: 274: 5482:"Pseudoprime Statistics and Tables" 4897: 4605: 4323:) = 1 then testing for congruence ( 4278: 4086: 3636: 3448:is found so that the Jacobi symbol 2264:(This search will never succeed if 1802: 1734: 1694: 1307: 1239: 981: 871: 609: 317: 53:Baillie-Wagstaff-Lucas pseudoprimes 3798:Lucas sequence-Algebraic relations 2233:. It is a good idea to check that 1197:) pair is an odd composite number 1028:that, in order to check equation ( 432:) above is true (see, page 1398). 25: 5555:Applications of Fibonacci Numbers 5202:10.1090/S0025-5718-1980-0572872-7 5018:10.1090/S0025-5718-1980-0583518-6 3494:. With this method for selecting 1632:strong Lucas pseudoprime in base 1042:need to compute all of the first 7592: 7200:Perfect digit-to-digit invariant 5661:"Extra Strong Lucas Pseudoprime" 4890: 4598: 4331:Solovay–Strassen primality test 4271: 4079: 3739:= −1, then we can adjust 3629: 1795: 1727: 1687: 1300: 1232: 974: 947:= −1, and we can compute 864: 602: 310: 5283:Robert Baillie; Andrew Fiori; 4901: 4891: 4690:which are also referred to as 4609: 4599: 4588: 4576: 4319:cannot be prime. Provided GCD( 4282: 4272: 4228: 4216: 4189: 4177: 4090: 4080: 4042: 4030: 3981: 3969: 3640: 3630: 2866: 2822: 2771: 2733: 2386: 2367: 2212: 2200: 2153:values, the average number of 1880: 1868: 1854:{\displaystyle 0\leq r<s-1} 1806: 1796: 1738: 1728: 1698: 1688: 1646:extra strong Lucas pseudoprime 1311: 1301: 1243: 1233: 1091: 1085: 985: 975: 875: 865: 613: 603: 321: 311: 298: 292: 212: 206: 152:be a positive integer and let 1: 6039:Expressible via specific sums 5356:10.1090/s0025-5718-97-00836-3 5261:10.1090/S0025-5718-00-01197-2 3295:). We then check congruence ( 2392:{\displaystyle O(\log _{2}n)} 1973:, one technique for choosing 1534:{\displaystyle c\cdot \log x} 5563:10.1007/978-94-011-2058-6_45 4718:strong Fibonacci pseudoprime 3178:= 44. Therefore, we compute 1159:{\displaystyle d\cdot 2^{s}} 457:) is true (see, page 1391). 7128:Multiplicative digital root 5182:"The pseudoprimes to 25·10" 4926:) = (2, −1) again defining 4805: 4726: 4709: 4656: 4494: 4385:) that declare a composite 4361:Miller–Rabin primality test 4325: 3997:{\displaystyle Q^{(n+1)/2}} 3861:{\displaystyle Q\neq \pm 1} 3832: 3814: 3716: 3698: 3692: 3530: 3301:) using our known value of 3297: 3041:does not change the result 1346: 1030: 675: 661: 648: 563: 453: 428: 387: 7640: 5642:"Strong Lucas Pseudoprime" 5334:Mathematics of Computation 5289:Mathematics of Computation 5230:Mathematics of Computation 5189:Mathematics of Computation 5005:Mathematics of Computation 4448:Baillie–PSW primality test 4419:+2) is the product of two 3808:, then 913 = 11·83 is the 3441:{\displaystyle D=P^{2}-4Q} 2245:. This method of choosing 906:For the next example, let 691:prime), but this does not 507:Baillie–PSW primality test 104:{\displaystyle D=P^{2}-4Q} 7588: 7571: 7557: 7535: 7521: 7499: 7485: 7463: 7449: 7422: 7409: 7205:Perfect digital invariant 7048: 7034: 6942: 6923: 6780:Superior highly composite 6666: 6649: 6577: 6564: 6532: 6519: 6407: 6396: 6099: 6086: 6044: 6033: 5996: 5985: 5933: 5919: 5882: 5871: 5824: 5809: 5727: 5713: 5464:Abstracts Amer. Math. Soc 4841:which may be written as: 4817:= −1; the sequence 4554:) = 1, then we also have 3063:At each stage, we reduce 2472:{\displaystyle V_{1}=P=1} 2226:{\displaystyle Q=(1-D)/4} 2149:). With this sequence of 1071:Strong Lucas pseudoprimes 6818:Euler's totient function 6602:Euler–Jacobi pseudoprime 5877:Other polynomial numbers 5226:"Frobenius Pseudoprimes" 4160:is prime, we must have, 3376:Lucas pseudoprimes, set 3030:{\displaystyle V_{2k+1}} 2943:is odd, replace it with 1626:-Fibonacci sequence and 1422:{\displaystyle P^{2}-4Q} 1191:strong Lucas pseudoprime 783:= 19. The Jacobi symbol 354:If this congruence does 6632:Somer–Lucas pseudoprime 6622:Lucas–Carmichael number 6457:Lazy caterer's sequence 5604:"Fibonacci Pseudoprime" 5285:Samuel S. Wagstaff, Jr. 5178:Samuel S. Wagstaff, Jr. 4994:Samuel S. Wagstaff, Jr. 4535:base 2. However, when 4407:= 9. The other is when 3930:{\displaystyle U_{n+1}} 3897:{\displaystyle Q^{n+1}} 3372:To calculate a list of 2432:{\displaystyle U_{1}=1} 2350:{\displaystyle V_{n+1}} 2317:{\displaystyle U_{n+1}} 374:, then this congruence 141:) be the corresponding 6507:Wedderburn–Etherington 5907:Lucky numbers of Euler 4909: 4724:for which congruence ( 4720:is a composite number 4654:for which congruence ( 4650:is a composite number 4620: 4454:Fibonacci pseudoprimes 4293: 4139: 4098: 3998: 3951: 3931: 3898: 3862: 3782: 3690:If either congruence ( 3651: 3585: 3488: 3442: 3396: 3117: 3097: 3077: 3031: 2995: 2937: 2881: 2786: 2691: 2578: 2519: 2496: 2473: 2433: 2393: 2351: 2318: 2227: 2181: 2143: 2092: 2021: 1952: 1887: 1855: 1814: 1746: 1616: 1589: 1555: 1535: 1503: 1483: 1463: 1443: 1423: 1387: 1367: 1319: 1251: 1180: 1160: 1127: 996: 941: 886: 814: 734:= 13, the sequence of 624: 555: 495: 332: 251: 183: 105: 35:Fibonacci pseudoprimes 6795:Prime omega functions 6612:Frobenius pseudoprime 6402:Combinatorial numbers 6271:Centered dodecahedral 6064:Primary pseudoperfect 5224:Jon Grantham (2001). 4910: 4809:) above is true with 4648:Fibonacci pseudoprime 4621: 4486:Fibonacci pseudoprime 4444:Fermat primality test 4294: 4140: 4099: 3999: 3952: 3932: 3899: 3863: 3788:remain unchanged and 3783: 3652: 3586: 3489: 3443: 3397: 3238:sequence, along with 3118: 3098: 3078: 3032: 2996: 2938: 2882: 2787: 2692: 2579: 2520: 2497: 2474: 2434: 2394: 2352: 2319: 2228: 2182: 2144: 2093: 2022: 1953: 1888: 1886:{\displaystyle (P,Q)} 1856: 1815: 1747: 1617: 1615:{\displaystyle V_{n}} 1590: 1588:{\displaystyle U_{n}} 1556: 1536: 1504: 1484: 1464: 1444: 1424: 1388: 1368: 1320: 1252: 1181: 1161: 1128: 997: 942: 903:a Lucas pseudoprime. 887: 815: 625: 556: 496: 443:) pair is a positive 393:Frobenius pseudoprime 333: 268:that does not divide 252: 184: 106: 18:Fibonacci pseudoprime 7254:-composition related 7054:Arithmetic functions 6656:Arithmetic functions 6592:Elliptic pseudoprime 6276:Centered icosahedral 6256:Centered tetrahedral 5429:Mathematics Magazine 4998:"Lucas Pseudoprimes" 4848: 4803:for which equation ( 4563: 4363:declare a composite 4359:applications of the 4169: 4112: 4022: 3961: 3941: 3908: 3875: 3843: 3755: 3600: 3549: 3545:is an odd prime and 3452: 3410: 3380: 3107: 3087: 3067: 3005: 2947: 2895: 2797: 2708: 2589: 2532: 2506: 2486: 2444: 2410: 2361: 2328: 2295: 2191: 2165: 2110: 2031: 1985: 1916: 1865: 1827: 1762: 1667: 1599: 1572: 1561:sufficiently large. 1545: 1513: 1493: 1473: 1453: 1433: 1397: 1377: 1357: 1267: 1212: 1170: 1137: 1079: 954: 914: 838: 787: 576: 516: 468: 451:for which equation ( 426:for which equation ( 412:Lucas probable prime 281: 200: 156: 73: 7180:Kaprekar's constant 6700:Colossally abundant 6587:Catalan pseudoprime 6487:Schröder–Hipparchus 6266:Centered octahedral 6142:Centered heptagonal 6132:Centered pentagonal 6122:Centered triangular 5722:and related numbers 5623:"Lucas Pseudoprime" 5585:Anderson, Peter G. 5579:Anderson, Peter G. 5523:Fibonacci Quarterly 5504:Fibonacci Quarterly 5397:Fibonacci Quarterly 5378:Fibonacci Quarterly 5252:2001MaCom..70..873G 5097:Richard E. Crandall 4734:= −1 and all 4011:is prime, then, by 3395:{\displaystyle Q=1} 3103:, and the power of 2680: 2659: 2622: 2180:{\displaystyle P=1} 1328:for some 0 ≤ 1061:= 1, 2, 3, ... are 820:is −1, so ÎŽ( 7598:Mathematics portal 7540:Aronson's sequence 7286:Smarandache–Wellin 7043:-dependent numbers 6750:Primitive abundant 6637:Strong pseudoprime 6627:Perrin pseudoprime 6607:Fermat pseudoprime 6547:Wolstenholme prime 6371:Squared triangular 6157:Centered decagonal 6152:Centered nonagonal 6147:Centered octagonal 6137:Centered hexagonal 5658:Weisstein, Eric W. 5639:Weisstein, Eric W. 5620:Weisstein, Eric W. 5601:Weisstein, Eric W. 5470:(83T–10–146): 197. 5425:V. E. Hoggatt, Jr. 5295:(330): 1931–1955. 5195:(151): 1003–1026. 5011:(152): 1391–1417. 4905: 4883: 4775:) for every prime 4616: 4533:Fermat pseudoprime 4439:for square roots. 4289: 4264: 4135: 4129: 4094: 4072: 3994: 3947: 3927: 3894: 3858: 3778: 3772: 3647: 3581: 3566: 3484: 3469: 3438: 3392: 3113: 3093: 3073: 3027: 2991: 2933: 2877: 2782: 2687: 2666: 2645: 2608: 2574: 2518:{\displaystyle 2k} 2515: 2492: 2469: 2429: 2389: 2347: 2314: 2223: 2177: 2139: 2127: 2088: 2073: 2048: 2017: 2002: 1948: 1933: 1909:for square roots. 1883: 1851: 1810: 1742: 1612: 1585: 1551: 1531: 1499: 1479: 1459: 1439: 1419: 1383: 1363: 1315: 1247: 1176: 1156: 1123: 1117: 992: 937: 931: 882: 810: 804: 620: 551: 533: 505:test, such as the 503:strong pseudoprime 491: 485: 328: 247: 238: 179: 173: 101: 31:Lucas pseudoprimes 7619:Fibonacci numbers 7606: 7605: 7584: 7583: 7553: 7552: 7517: 7516: 7481: 7480: 7445: 7444: 7405: 7404: 7401: 7400: 7220: 7219: 7030: 7029: 6919: 6918: 6915: 6914: 6861:Aliquot sequences 6672:Divisor functions 6645: 6644: 6617:Lucas pseudoprime 6597:Euler pseudoprime 6582:Carmichael number 6560: 6559: 6515: 6514: 6392: 6391: 6388: 6387: 6384: 6383: 6345: 6344: 6233: 6232: 6190:Square triangular 6082: 6081: 6029: 6028: 5981: 5980: 5915: 5914: 5867: 5866: 5805: 5804: 5311:10.1090/mcom/3616 5174:John L. Selfridge 5077:978-1-930190-10-8 4882: 4854: 4791:Pell pseudoprimes 4751:Carmichael number 4640: 4639: 4546:is prime and GCD( 4313: 4312: 4263: 4128: 4071: 4013:Euler's criterion 3950:{\displaystyle Q} 3771: 3706:is not prime. If 3671: 3670: 3565: 3468: 3116:{\displaystyle Q} 3096:{\displaystyle V} 3076:{\displaystyle U} 2685: 2495:{\displaystyle k} 2403:. To start off, 2257:was suggested by 2126: 2072: 2047: 2001: 1932: 1705: 1554:{\displaystyle x} 1502:{\displaystyle x} 1482:{\displaystyle Q} 1462:{\displaystyle P} 1442:{\displaystyle c} 1386:{\displaystyle Q} 1366:{\displaystyle P} 1179:{\displaystyle d} 1116: 1046:+ 1 terms in the 930: 803: 644: 643: 532: 484: 437:Lucas pseudoprime 422:positive integer 380:primality testing 352: 351: 237: 172: 16:(Redirected from 7631: 7596: 7559: 7528:Natural language 7523: 7487: 7455:Generated via a 7451: 7411: 7316:Digit-reassembly 7281:Self-descriptive 7085: 7050: 7036: 6987:Lucas–Carmichael 6977:Harmonic divisor 6925: 6851:Sparsely totient 6826:Highly cototient 6735:Multiply perfect 6725:Highly composite 6668: 6651: 6566: 6521: 6502:Telephone number 6398: 6356: 6337:Square pyramidal 6319:Stella octangula 6244: 6110: 6101: 6093:Figurate numbers 6088: 6035: 5987: 5921: 5873: 5811: 5715: 5699: 5692: 5685: 5676: 5671: 5670: 5652: 5651: 5633: 5632: 5614: 5613: 5567: 5566: 5550: 5541: 5540: 5538: 5518: 5512: 5511: 5499: 5493: 5492: 5490: 5488: 5478: 5472: 5471: 5459: 5453: 5452: 5421: 5415: 5414: 5412: 5392: 5386: 5385: 5375: 5366: 5360: 5359: 5349: 5340:(218): 869–881. 5329: 5323: 5322: 5304: 5280: 5274: 5273: 5263: 5245: 5236:(234): 873–891. 5221: 5215: 5214: 5204: 5186: 5166: 5160: 5159: 5134: 5123: 5122: 5107:(2nd ed.). 5093: 5082: 5081: 5069: 5052: 5039: 5038: 5020: 5002: 4996:(October 1980). 4992:Robert Baillie; 4989: 4914: 4912: 4911: 4906: 4904: 4888: 4884: 4875: 4865: 4864: 4855: 4852: 4840: 4797:Pell pseudoprime 4763:− 1) or 2( 4702: 4681: 4634: 4625: 4623: 4622: 4617: 4612: 4575: 4574: 4557: 4515: 4466:= −1, the 4381:) pairs (modulo 4307: 4298: 4296: 4295: 4290: 4285: 4269: 4265: 4256: 4240: 4239: 4235: 4201: 4200: 4196: 4163: 4144: 4142: 4141: 4136: 4134: 4130: 4121: 4103: 4101: 4100: 4095: 4093: 4077: 4073: 4064: 4054: 4053: 4049: 4003: 4001: 4000: 3995: 3993: 3992: 3988: 3956: 3954: 3953: 3948: 3936: 3934: 3933: 3928: 3926: 3925: 3903: 3901: 3900: 3895: 3893: 3892: 3867: 3865: 3864: 3859: 3787: 3785: 3784: 3779: 3777: 3773: 3764: 3735:happened to set 3665: 3656: 3654: 3653: 3648: 3643: 3618: 3617: 3594: 3590: 3588: 3587: 3582: 3571: 3567: 3558: 3515: 3493: 3491: 3490: 3485: 3474: 3470: 3461: 3447: 3445: 3444: 3439: 3428: 3427: 3401: 3399: 3398: 3393: 3364: 3328: 3122: 3120: 3119: 3114: 3102: 3100: 3099: 3094: 3082: 3080: 3079: 3074: 3036: 3034: 3033: 3028: 3026: 3025: 3000: 2998: 2997: 2992: 2984: 2983: 2968: 2967: 2942: 2940: 2939: 2934: 2932: 2931: 2916: 2915: 2886: 2884: 2883: 2878: 2873: 2865: 2864: 2843: 2842: 2818: 2817: 2791: 2789: 2788: 2783: 2778: 2770: 2769: 2754: 2753: 2729: 2728: 2696: 2694: 2693: 2688: 2686: 2681: 2679: 2674: 2658: 2653: 2643: 2638: 2637: 2621: 2616: 2604: 2603: 2583: 2581: 2580: 2575: 2573: 2572: 2560: 2559: 2547: 2546: 2524: 2522: 2521: 2516: 2501: 2499: 2498: 2493: 2478: 2476: 2475: 2470: 2456: 2455: 2438: 2436: 2435: 2430: 2422: 2421: 2398: 2396: 2395: 2390: 2379: 2378: 2356: 2354: 2353: 2348: 2346: 2345: 2323: 2321: 2320: 2315: 2313: 2312: 2232: 2230: 2229: 2224: 2219: 2186: 2184: 2183: 2178: 2148: 2146: 2145: 2140: 2132: 2128: 2119: 2097: 2095: 2094: 2089: 2078: 2074: 2068: 2060: 2053: 2049: 2040: 2026: 2024: 2023: 2018: 2007: 2003: 1994: 1957: 1955: 1954: 1949: 1938: 1934: 1925: 1892: 1890: 1889: 1884: 1860: 1858: 1857: 1852: 1819: 1817: 1816: 1811: 1809: 1787: 1786: 1785: 1784: 1751: 1749: 1748: 1743: 1741: 1716: 1715: 1706: 1703: 1701: 1679: 1678: 1621: 1619: 1618: 1613: 1611: 1610: 1594: 1592: 1591: 1586: 1584: 1583: 1560: 1558: 1557: 1552: 1540: 1538: 1537: 1532: 1509:is greater than 1508: 1506: 1505: 1500: 1488: 1486: 1485: 1480: 1468: 1466: 1465: 1460: 1448: 1446: 1445: 1440: 1428: 1426: 1425: 1420: 1409: 1408: 1392: 1390: 1389: 1384: 1372: 1370: 1369: 1364: 1324: 1322: 1321: 1316: 1314: 1292: 1291: 1290: 1289: 1256: 1254: 1253: 1248: 1246: 1224: 1223: 1185: 1183: 1182: 1177: 1165: 1163: 1162: 1157: 1155: 1154: 1132: 1130: 1129: 1124: 1122: 1118: 1109: 1001: 999: 998: 993: 988: 966: 965: 946: 944: 943: 938: 936: 932: 923: 891: 889: 888: 883: 878: 850: 849: 819: 817: 816: 811: 809: 805: 796: 747: 730:= −1, and 679:) is true, then 665:) is true, then 638: 629: 627: 626: 621: 616: 594: 593: 570: 560: 558: 557: 552: 538: 534: 525: 500: 498: 497: 492: 490: 486: 477: 385:The congruence ( 346: 337: 335: 334: 329: 324: 302: 301: 275: 256: 254: 253: 248: 243: 239: 230: 188: 186: 185: 180: 178: 174: 165: 110: 108: 107: 102: 91: 90: 21: 7639: 7638: 7634: 7633: 7632: 7630: 7629: 7628: 7609: 7608: 7607: 7602: 7580: 7576:Strobogrammatic 7567: 7549: 7531: 7513: 7495: 7477: 7459: 7441: 7418: 7397: 7381: 7340:Divisor-related 7335: 7295: 7246: 7216: 7153: 7137: 7116: 7083: 7056: 7044: 7026: 6938: 6937:related numbers 6911: 6888: 6855: 6846:Perfect totient 6812: 6789: 6720:Highly abundant 6662: 6641: 6573: 6556: 6528: 6511: 6497:Stirling second 6403: 6380: 6341: 6323: 6280: 6229: 6166: 6127:Centered square 6095: 6078: 6040: 6025: 5992: 5977: 5929: 5928:defined numbers 5911: 5878: 5863: 5834:Double Mersenne 5820: 5801: 5723: 5709: 5707:natural numbers 5703: 5656: 5655: 5637: 5636: 5618: 5617: 5599: 5598: 5591:Jacobsen, Dana 5576: 5571: 5570: 5552: 5551: 5544: 5536:10.1.1.376.2601 5520: 5519: 5515: 5501: 5500: 5496: 5486: 5484: 5480: 5479: 5475: 5461: 5460: 5456: 5441:10.2307/2689212 5423: 5422: 5418: 5410:10.1.1.388.4993 5394: 5393: 5389: 5373: 5368: 5367: 5363: 5347:10.1.1.192.4789 5331: 5330: 5326: 5282: 5281: 5277: 5223: 5222: 5218: 5184: 5168: 5167: 5163: 5156: 5146:Springer-Verlag 5138:Paulo Ribenboim 5136: 5135: 5126: 5119: 5109:Springer-Verlag 5095: 5094: 5085: 5078: 5054: 5053: 5042: 5000: 4991: 4990: 4959: 4954: 4931: 4869: 4856: 4846: 4845: 4832: 4824:then being the 4822: 4793: 4698: 4677: 4632: 4566: 4561: 4560: 4511: 4471: 4456: 4437:Newton's method 4354: 4305: 4250: 4211: 4172: 4167: 4166: 4147:Legendre symbol 4115: 4110: 4109: 4058: 4025: 4020: 4019: 3964: 3959: 3958: 3939: 3938: 3911: 3906: 3905: 3878: 3873: 3872: 3841: 3840: 3758: 3753: 3752: 3685: 3678: 3663: 3603: 3598: 3597: 3552: 3547: 3546: 3526: 3511: 3506:, the first 10 3455: 3450: 3449: 3419: 3408: 3407: 3378: 3377: 3360: 3324: 3306: 3285: 3278: 3233: 3226: 3219: 3212: 3205: 3198: 3191: 3184: 3177: 3173: 3169: 3165: 3161: 3157: 3153: 3149: 3105: 3104: 3085: 3084: 3065: 3064: 3008: 3003: 3002: 2972: 2956: 2945: 2944: 2920: 2904: 2893: 2892: 2853: 2831: 2800: 2795: 2794: 2758: 2742: 2711: 2706: 2705: 2644: 2629: 2592: 2587: 2586: 2564: 2551: 2535: 2530: 2529: 2504: 2503: 2484: 2483: 2447: 2442: 2441: 2413: 2408: 2407: 2370: 2359: 2358: 2331: 2326: 2325: 2298: 2293: 2292: 2189: 2188: 2163: 2162: 2113: 2108: 2107: 2061: 2054: 2034: 2029: 2028: 1988: 1983: 1982: 1919: 1914: 1913: 1907:Newton's method 1899: 1863: 1862: 1825: 1824: 1776: 1765: 1760: 1759: 1707: 1704: and  1670: 1665: 1664: 1602: 1597: 1596: 1575: 1570: 1569: 1543: 1542: 1511: 1510: 1491: 1490: 1471: 1470: 1451: 1450: 1431: 1430: 1400: 1395: 1394: 1375: 1374: 1355: 1354: 1281: 1270: 1265: 1264: 1215: 1210: 1209: 1168: 1167: 1146: 1135: 1134: 1103: 1077: 1076: 1073: 957: 952: 951: 917: 912: 911: 910:= 119. We have 841: 836: 835: 829: 790: 785: 784: 774: 767: 760: 753: 739: 659:If congruence ( 646:If congruence ( 636: 579: 574: 573: 561:then equation ( 519: 514: 513: 471: 466: 465: 408: 344: 284: 279: 278: 224: 198: 197: 159: 154: 153: 143:Lucas sequences 131: 116: 82: 71: 70: 55: 28: 23: 22: 15: 12: 11: 5: 7637: 7635: 7627: 7626: 7621: 7611: 7610: 7604: 7603: 7601: 7600: 7589: 7586: 7585: 7582: 7581: 7579: 7578: 7572: 7569: 7568: 7562: 7555: 7554: 7551: 7550: 7548: 7547: 7542: 7536: 7533: 7532: 7526: 7519: 7518: 7515: 7514: 7512: 7511: 7509:Sorting number 7506: 7504:Pancake number 7500: 7497: 7496: 7490: 7483: 7482: 7479: 7478: 7476: 7475: 7470: 7464: 7461: 7460: 7454: 7447: 7446: 7443: 7442: 7440: 7439: 7434: 7429: 7423: 7420: 7419: 7416:Binary numbers 7414: 7407: 7406: 7403: 7402: 7399: 7398: 7396: 7395: 7389: 7387: 7383: 7382: 7380: 7379: 7374: 7369: 7364: 7359: 7354: 7349: 7343: 7341: 7337: 7336: 7334: 7333: 7328: 7323: 7318: 7313: 7307: 7305: 7297: 7296: 7294: 7293: 7288: 7283: 7278: 7273: 7268: 7263: 7257: 7255: 7248: 7247: 7245: 7244: 7243: 7242: 7231: 7229: 7226:P-adic numbers 7222: 7221: 7218: 7217: 7215: 7214: 7213: 7212: 7202: 7197: 7192: 7187: 7182: 7177: 7172: 7167: 7161: 7159: 7155: 7154: 7152: 7151: 7145: 7143: 7142:Coding-related 7139: 7138: 7136: 7135: 7130: 7124: 7122: 7118: 7117: 7115: 7114: 7109: 7104: 7099: 7093: 7091: 7082: 7081: 7080: 7079: 7077:Multiplicative 7074: 7063: 7061: 7046: 7045: 7041:Numeral system 7039: 7032: 7031: 7028: 7027: 7025: 7024: 7019: 7014: 7009: 7004: 6999: 6994: 6989: 6984: 6979: 6974: 6969: 6964: 6959: 6954: 6949: 6943: 6940: 6939: 6928: 6921: 6920: 6917: 6916: 6913: 6912: 6910: 6909: 6904: 6898: 6896: 6890: 6889: 6887: 6886: 6881: 6876: 6871: 6865: 6863: 6857: 6856: 6854: 6853: 6848: 6843: 6838: 6833: 6831:Highly totient 6828: 6822: 6820: 6814: 6813: 6811: 6810: 6805: 6799: 6797: 6791: 6790: 6788: 6787: 6782: 6777: 6772: 6767: 6762: 6757: 6752: 6747: 6742: 6737: 6732: 6727: 6722: 6717: 6712: 6707: 6702: 6697: 6692: 6687: 6685:Almost perfect 6682: 6676: 6674: 6664: 6663: 6654: 6647: 6646: 6643: 6642: 6640: 6639: 6634: 6629: 6624: 6619: 6614: 6609: 6604: 6599: 6594: 6589: 6584: 6578: 6575: 6574: 6569: 6562: 6561: 6558: 6557: 6555: 6554: 6549: 6544: 6539: 6533: 6530: 6529: 6524: 6517: 6516: 6513: 6512: 6510: 6509: 6504: 6499: 6494: 6492:Stirling first 6489: 6484: 6479: 6474: 6469: 6464: 6459: 6454: 6449: 6444: 6439: 6434: 6429: 6424: 6419: 6414: 6408: 6405: 6404: 6401: 6394: 6393: 6390: 6389: 6386: 6385: 6382: 6381: 6379: 6378: 6373: 6368: 6362: 6360: 6353: 6347: 6346: 6343: 6342: 6340: 6339: 6333: 6331: 6325: 6324: 6322: 6321: 6316: 6311: 6306: 6301: 6296: 6290: 6288: 6282: 6281: 6279: 6278: 6273: 6268: 6263: 6258: 6252: 6250: 6241: 6235: 6234: 6231: 6230: 6228: 6227: 6222: 6217: 6212: 6207: 6202: 6197: 6192: 6187: 6182: 6176: 6174: 6168: 6167: 6165: 6164: 6159: 6154: 6149: 6144: 6139: 6134: 6129: 6124: 6118: 6116: 6107: 6097: 6096: 6091: 6084: 6083: 6080: 6079: 6077: 6076: 6071: 6066: 6061: 6056: 6051: 6045: 6042: 6041: 6038: 6031: 6030: 6027: 6026: 6024: 6023: 6018: 6013: 6008: 6003: 5997: 5994: 5993: 5990: 5983: 5982: 5979: 5978: 5976: 5975: 5970: 5965: 5960: 5955: 5950: 5945: 5940: 5934: 5931: 5930: 5924: 5917: 5916: 5913: 5912: 5910: 5909: 5904: 5899: 5894: 5889: 5883: 5880: 5879: 5876: 5869: 5868: 5865: 5864: 5862: 5861: 5856: 5851: 5846: 5841: 5836: 5831: 5825: 5822: 5821: 5814: 5807: 5806: 5803: 5802: 5800: 5799: 5794: 5789: 5784: 5779: 5774: 5769: 5764: 5759: 5754: 5749: 5744: 5739: 5734: 5728: 5725: 5724: 5718: 5711: 5710: 5704: 5702: 5701: 5694: 5687: 5679: 5673: 5672: 5653: 5634: 5615: 5596: 5589: 5583: 5575: 5574:External links 5572: 5569: 5568: 5542: 5513: 5494: 5473: 5454: 5435:(4): 210–214. 5416: 5387: 5361: 5324: 5275: 5216: 5170:Carl Pomerance 5161: 5154: 5124: 5117: 5101:Carl Pomerance 5083: 5076: 5056:David Bressoud 5040: 4956: 4955: 4953: 4950: 4929: 4916: 4915: 4903: 4900: 4896: 4893: 4887: 4881: 4878: 4872: 4868: 4863: 4859: 4820: 4792: 4789: 4785: 4784: 4753: 4692:Bruckman-Lucas 4688: 4687: 4670: 4669: 4638: 4637: 4628: 4626: 4615: 4611: 4608: 4604: 4601: 4596: 4593: 4590: 4587: 4584: 4581: 4578: 4573: 4569: 4522: 4521: 4469: 4455: 4452: 4353: 4350: 4348:is not prime. 4311: 4310: 4301: 4299: 4288: 4284: 4281: 4277: 4274: 4268: 4262: 4259: 4253: 4249: 4246: 4243: 4238: 4234: 4230: 4227: 4224: 4221: 4218: 4214: 4210: 4207: 4204: 4199: 4195: 4191: 4188: 4185: 4182: 4179: 4175: 4156:Therefore, if 4133: 4127: 4124: 4118: 4106: 4105: 4092: 4089: 4085: 4082: 4076: 4070: 4067: 4061: 4057: 4052: 4048: 4044: 4041: 4038: 4035: 4032: 4028: 3991: 3987: 3983: 3980: 3977: 3974: 3971: 3967: 3946: 3924: 3921: 3918: 3914: 3891: 3888: 3885: 3881: 3857: 3854: 3851: 3848: 3776: 3770: 3767: 3761: 3683: 3676: 3669: 3668: 3659: 3657: 3646: 3642: 3639: 3635: 3632: 3627: 3624: 3621: 3616: 3613: 3610: 3606: 3580: 3577: 3574: 3570: 3564: 3561: 3555: 3525: 3522: 3483: 3480: 3477: 3473: 3467: 3464: 3458: 3437: 3434: 3431: 3426: 3422: 3418: 3415: 3391: 3388: 3385: 3304: 3283: 3276: 3231: 3224: 3217: 3210: 3203: 3196: 3189: 3182: 3175: 3171: 3167: 3163: 3159: 3155: 3151: 3147: 3112: 3092: 3072: 3024: 3021: 3018: 3015: 3011: 2990: 2987: 2982: 2979: 2975: 2971: 2966: 2963: 2959: 2955: 2952: 2930: 2927: 2923: 2919: 2914: 2911: 2907: 2903: 2900: 2889: 2888: 2876: 2872: 2868: 2863: 2860: 2856: 2852: 2849: 2846: 2841: 2838: 2834: 2830: 2827: 2824: 2821: 2816: 2813: 2810: 2807: 2803: 2792: 2781: 2777: 2773: 2768: 2765: 2761: 2757: 2752: 2749: 2745: 2741: 2738: 2735: 2732: 2727: 2724: 2721: 2718: 2714: 2699: 2698: 2684: 2678: 2673: 2669: 2665: 2662: 2657: 2652: 2648: 2641: 2636: 2632: 2628: 2625: 2620: 2615: 2611: 2607: 2602: 2599: 2595: 2584: 2571: 2567: 2563: 2558: 2554: 2550: 2545: 2542: 2538: 2514: 2511: 2491: 2480: 2479: 2468: 2465: 2462: 2459: 2454: 2450: 2439: 2428: 2425: 2420: 2416: 2388: 2385: 2382: 2377: 2373: 2369: 2366: 2344: 2341: 2338: 2334: 2311: 2308: 2305: 2301: 2259:John Selfridge 2222: 2218: 2214: 2211: 2208: 2205: 2202: 2199: 2196: 2176: 2173: 2170: 2138: 2135: 2131: 2125: 2122: 2116: 2087: 2084: 2081: 2077: 2071: 2067: 2064: 2057: 2052: 2046: 2043: 2037: 2016: 2013: 2010: 2006: 2000: 1997: 1991: 1947: 1944: 1941: 1937: 1931: 1928: 1922: 1898: 1895: 1882: 1879: 1876: 1873: 1870: 1850: 1847: 1844: 1841: 1838: 1835: 1832: 1821: 1820: 1808: 1805: 1801: 1798: 1793: 1790: 1783: 1779: 1775: 1772: 1768: 1753: 1752: 1740: 1737: 1733: 1730: 1725: 1722: 1719: 1714: 1710: 1700: 1697: 1693: 1690: 1685: 1682: 1677: 1673: 1609: 1605: 1582: 1578: 1550: 1530: 1527: 1524: 1521: 1518: 1498: 1478: 1458: 1449:(depending on 1438: 1418: 1415: 1412: 1407: 1403: 1382: 1362: 1326: 1325: 1313: 1310: 1306: 1303: 1298: 1295: 1288: 1284: 1280: 1277: 1273: 1258: 1257: 1245: 1242: 1238: 1235: 1230: 1227: 1222: 1218: 1175: 1153: 1149: 1145: 1142: 1133:into the form 1121: 1115: 1112: 1106: 1102: 1099: 1096: 1093: 1090: 1087: 1084: 1072: 1069: 1068: 1067: 1034:) for a given 1003: 1002: 991: 987: 984: 980: 977: 972: 969: 964: 960: 935: 929: 926: 920: 893: 892: 881: 877: 874: 870: 867: 862: 859: 856: 853: 848: 844: 827: 808: 802: 799: 793: 772: 765: 758: 751: 656:is composite. 642: 641: 632: 630: 619: 615: 612: 608: 605: 600: 597: 592: 589: 586: 582: 550: 547: 544: 541: 537: 531: 528: 522: 489: 483: 480: 474: 407: 404: 350: 349: 340: 338: 327: 323: 320: 316: 313: 308: 305: 300: 297: 294: 291: 287: 258: 257: 246: 242: 236: 233: 227: 223: 220: 217: 214: 211: 208: 205: 177: 171: 168: 162: 129: 114: 100: 97: 94: 89: 85: 81: 78: 54: 51: 47:Lucas sequence 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 7636: 7625: 7622: 7620: 7617: 7616: 7614: 7599: 7595: 7591: 7590: 7587: 7577: 7574: 7573: 7570: 7565: 7560: 7556: 7546: 7543: 7541: 7538: 7537: 7534: 7529: 7524: 7520: 7510: 7507: 7505: 7502: 7501: 7498: 7493: 7488: 7484: 7474: 7471: 7469: 7466: 7465: 7462: 7458: 7452: 7448: 7438: 7435: 7433: 7430: 7428: 7425: 7424: 7421: 7417: 7412: 7408: 7394: 7391: 7390: 7388: 7384: 7378: 7375: 7373: 7370: 7368: 7367:Polydivisible 7365: 7363: 7360: 7358: 7355: 7353: 7350: 7348: 7345: 7344: 7342: 7338: 7332: 7329: 7327: 7324: 7322: 7319: 7317: 7314: 7312: 7309: 7308: 7306: 7303: 7298: 7292: 7289: 7287: 7284: 7282: 7279: 7277: 7274: 7272: 7269: 7267: 7264: 7262: 7259: 7258: 7256: 7253: 7249: 7241: 7238: 7237: 7236: 7233: 7232: 7230: 7227: 7223: 7211: 7208: 7207: 7206: 7203: 7201: 7198: 7196: 7193: 7191: 7188: 7186: 7183: 7181: 7178: 7176: 7173: 7171: 7168: 7166: 7163: 7162: 7160: 7156: 7150: 7147: 7146: 7144: 7140: 7134: 7131: 7129: 7126: 7125: 7123: 7121:Digit product 7119: 7113: 7110: 7108: 7105: 7103: 7100: 7098: 7095: 7094: 7092: 7090: 7086: 7078: 7075: 7073: 7070: 7069: 7068: 7065: 7064: 7062: 7060: 7055: 7051: 7047: 7042: 7037: 7033: 7023: 7020: 7018: 7015: 7013: 7010: 7008: 7005: 7003: 7000: 6998: 6995: 6993: 6990: 6988: 6985: 6983: 6980: 6978: 6975: 6973: 6970: 6968: 6965: 6963: 6960: 6958: 6957:ErdƑs–Nicolas 6955: 6953: 6950: 6948: 6945: 6944: 6941: 6936: 6932: 6926: 6922: 6908: 6905: 6903: 6900: 6899: 6897: 6895: 6891: 6885: 6882: 6880: 6877: 6875: 6872: 6870: 6867: 6866: 6864: 6862: 6858: 6852: 6849: 6847: 6844: 6842: 6839: 6837: 6834: 6832: 6829: 6827: 6824: 6823: 6821: 6819: 6815: 6809: 6806: 6804: 6801: 6800: 6798: 6796: 6792: 6786: 6783: 6781: 6778: 6776: 6775:Superabundant 6773: 6771: 6768: 6766: 6763: 6761: 6758: 6756: 6753: 6751: 6748: 6746: 6743: 6741: 6738: 6736: 6733: 6731: 6728: 6726: 6723: 6721: 6718: 6716: 6713: 6711: 6708: 6706: 6703: 6701: 6698: 6696: 6693: 6691: 6688: 6686: 6683: 6681: 6678: 6677: 6675: 6673: 6669: 6665: 6661: 6657: 6652: 6648: 6638: 6635: 6633: 6630: 6628: 6625: 6623: 6620: 6618: 6615: 6613: 6610: 6608: 6605: 6603: 6600: 6598: 6595: 6593: 6590: 6588: 6585: 6583: 6580: 6579: 6576: 6572: 6567: 6563: 6553: 6550: 6548: 6545: 6543: 6540: 6538: 6535: 6534: 6531: 6527: 6522: 6518: 6508: 6505: 6503: 6500: 6498: 6495: 6493: 6490: 6488: 6485: 6483: 6480: 6478: 6475: 6473: 6470: 6468: 6465: 6463: 6460: 6458: 6455: 6453: 6450: 6448: 6445: 6443: 6440: 6438: 6435: 6433: 6430: 6428: 6425: 6423: 6420: 6418: 6415: 6413: 6410: 6409: 6406: 6399: 6395: 6377: 6374: 6372: 6369: 6367: 6364: 6363: 6361: 6357: 6354: 6352: 6351:4-dimensional 6348: 6338: 6335: 6334: 6332: 6330: 6326: 6320: 6317: 6315: 6312: 6310: 6307: 6305: 6302: 6300: 6297: 6295: 6292: 6291: 6289: 6287: 6283: 6277: 6274: 6272: 6269: 6267: 6264: 6262: 6261:Centered cube 6259: 6257: 6254: 6253: 6251: 6249: 6245: 6242: 6240: 6239:3-dimensional 6236: 6226: 6223: 6221: 6218: 6216: 6213: 6211: 6208: 6206: 6203: 6201: 6198: 6196: 6193: 6191: 6188: 6186: 6183: 6181: 6178: 6177: 6175: 6173: 6169: 6163: 6160: 6158: 6155: 6153: 6150: 6148: 6145: 6143: 6140: 6138: 6135: 6133: 6130: 6128: 6125: 6123: 6120: 6119: 6117: 6115: 6111: 6108: 6106: 6105:2-dimensional 6102: 6098: 6094: 6089: 6085: 6075: 6072: 6070: 6067: 6065: 6062: 6060: 6057: 6055: 6052: 6050: 6049:Nonhypotenuse 6047: 6046: 6043: 6036: 6032: 6022: 6019: 6017: 6014: 6012: 6009: 6007: 6004: 6002: 5999: 5998: 5995: 5988: 5984: 5974: 5971: 5969: 5966: 5964: 5961: 5959: 5956: 5954: 5951: 5949: 5946: 5944: 5941: 5939: 5936: 5935: 5932: 5927: 5922: 5918: 5908: 5905: 5903: 5900: 5898: 5895: 5893: 5890: 5888: 5885: 5884: 5881: 5874: 5870: 5860: 5857: 5855: 5852: 5850: 5847: 5845: 5842: 5840: 5837: 5835: 5832: 5830: 5827: 5826: 5823: 5818: 5812: 5808: 5798: 5795: 5793: 5790: 5788: 5787:Perfect power 5785: 5783: 5780: 5778: 5777:Seventh power 5775: 5773: 5770: 5768: 5765: 5763: 5760: 5758: 5755: 5753: 5750: 5748: 5745: 5743: 5740: 5738: 5735: 5733: 5730: 5729: 5726: 5721: 5716: 5712: 5708: 5700: 5695: 5693: 5688: 5686: 5681: 5680: 5677: 5668: 5667: 5662: 5659: 5654: 5649: 5648: 5643: 5640: 5635: 5630: 5629: 5624: 5621: 5616: 5611: 5610: 5605: 5602: 5597: 5594: 5590: 5588: 5584: 5582: 5578: 5577: 5573: 5564: 5560: 5556: 5549: 5547: 5543: 5537: 5532: 5528: 5524: 5517: 5514: 5509: 5505: 5498: 5495: 5483: 5477: 5474: 5469: 5465: 5458: 5455: 5450: 5446: 5442: 5438: 5434: 5430: 5426: 5420: 5417: 5411: 5406: 5402: 5398: 5391: 5388: 5384:(3): 232–242. 5383: 5379: 5372: 5365: 5362: 5357: 5353: 5348: 5343: 5339: 5335: 5328: 5325: 5320: 5316: 5312: 5308: 5303: 5298: 5294: 5290: 5286: 5279: 5276: 5271: 5267: 5262: 5257: 5253: 5249: 5244: 5239: 5235: 5231: 5227: 5220: 5217: 5212: 5208: 5203: 5198: 5194: 5190: 5183: 5180:(July 1980). 5179: 5175: 5171: 5165: 5162: 5157: 5155:0-387-94457-5 5151: 5147: 5143: 5139: 5133: 5131: 5129: 5125: 5120: 5118:0-387-25282-7 5114: 5110: 5106: 5102: 5098: 5092: 5090: 5088: 5084: 5079: 5073: 5068: 5067: 5061: 5057: 5051: 5049: 5047: 5045: 5041: 5036: 5032: 5028: 5024: 5019: 5014: 5010: 5006: 4999: 4995: 4988: 4986: 4984: 4982: 4980: 4978: 4976: 4974: 4972: 4970: 4968: 4966: 4964: 4962: 4958: 4951: 4949: 4947: 4943: 4938: 4936: 4935:Pell sequence 4932: 4925: 4921: 4898: 4894: 4885: 4879: 4876: 4870: 4866: 4861: 4857: 4844: 4843: 4842: 4839: 4835: 4829: 4827: 4826:Pell sequence 4823: 4816: 4812: 4808: 4807: 4802: 4798: 4790: 4788: 4782: 4778: 4774: 4770: 4766: 4762: 4758: 4754: 4752: 4748: 4745: 4744: 4743: 4741: 4737: 4733: 4729: 4728: 4723: 4719: 4714: 4712: 4711: 4706: 4701: 4695: 4693: 4685: 4680: 4675: 4674: 4673: 4667: 4663: 4660:) holds with 4659: 4658: 4653: 4649: 4645: 4644: 4643: 4636: 4629: 4627: 4613: 4606: 4602: 4594: 4591: 4585: 4582: 4579: 4571: 4567: 4559: 4558: 4555: 4553: 4549: 4545: 4540: 4538: 4534: 4530: 4525: 4519: 4514: 4509: 4508: 4507: 4505: 4501: 4498:) holds with 4497: 4496: 4491: 4487: 4482: 4480: 4476: 4472: 4465: 4461: 4453: 4451: 4449: 4445: 4440: 4438: 4434: 4430: 4426: 4422: 4418: 4414: 4410: 4406: 4401: 4399: 4395: 4390: 4388: 4384: 4380: 4376: 4371: 4368: 4366: 4362: 4358: 4351: 4349: 4347: 4343: 4339: 4334: 4332: 4328: 4327: 4322: 4318: 4309: 4302: 4300: 4286: 4279: 4275: 4266: 4260: 4257: 4251: 4247: 4244: 4241: 4236: 4232: 4225: 4222: 4219: 4212: 4208: 4205: 4202: 4197: 4193: 4186: 4183: 4180: 4173: 4165: 4164: 4161: 4159: 4154: 4152: 4148: 4131: 4125: 4122: 4116: 4087: 4083: 4074: 4068: 4065: 4059: 4055: 4050: 4046: 4039: 4036: 4033: 4026: 4018: 4017: 4016: 4014: 4010: 4005: 3989: 3985: 3978: 3975: 3972: 3965: 3944: 3922: 3919: 3916: 3912: 3889: 3886: 3883: 3879: 3869: 3855: 3852: 3849: 3846: 3837: 3835: 3834: 3829: 3825: 3821: 3817: 3816: 3811: 3807: 3803: 3799: 3795: 3791: 3774: 3768: 3765: 3759: 3750: 3746: 3742: 3738: 3734: 3730: 3726: 3721: 3719: 3718: 3713: 3709: 3705: 3701: 3700: 3695: 3694: 3688: 3686: 3679: 3667: 3660: 3658: 3644: 3637: 3633: 3625: 3622: 3619: 3614: 3611: 3608: 3604: 3596: 3595: 3592: 3578: 3575: 3572: 3568: 3562: 3559: 3553: 3544: 3539: 3537: 3533: 3532: 3523: 3521: 3519: 3514: 3509: 3505: 3501: 3497: 3481: 3478: 3475: 3471: 3465: 3462: 3456: 3435: 3432: 3429: 3424: 3420: 3416: 3413: 3405: 3389: 3386: 3383: 3375: 3370: 3368: 3363: 3358: 3354: 3350: 3346: 3341: 3339: 3334: 3332: 3327: 3322: 3318: 3314: 3309: 3307: 3300: 3299: 3294: 3290: 3286: 3279: 3271: 3269: 3265: 3261: 3257: 3253: 3249: 3245: 3241: 3237: 3230: 3223: 3216: 3209: 3202: 3195: 3188: 3181: 3145: 3141: 3138:terms in the 3137: 3134:to determine 3133: 3128: 3126: 3110: 3090: 3070: 3061: 3059: 3055: 3051: 3047: 3044: 3040: 3022: 3019: 3016: 3013: 3009: 2988: 2985: 2980: 2977: 2973: 2969: 2964: 2961: 2957: 2953: 2950: 2928: 2925: 2921: 2917: 2912: 2909: 2905: 2901: 2898: 2874: 2870: 2861: 2858: 2854: 2850: 2847: 2844: 2839: 2836: 2832: 2828: 2825: 2819: 2814: 2811: 2808: 2805: 2801: 2793: 2779: 2775: 2766: 2763: 2759: 2755: 2750: 2747: 2743: 2739: 2736: 2730: 2725: 2722: 2719: 2716: 2712: 2704: 2703: 2702: 2682: 2676: 2671: 2667: 2663: 2660: 2655: 2650: 2646: 2639: 2634: 2630: 2626: 2623: 2618: 2613: 2609: 2605: 2600: 2597: 2593: 2585: 2569: 2565: 2561: 2556: 2552: 2548: 2543: 2540: 2536: 2528: 2527: 2526: 2512: 2509: 2489: 2466: 2463: 2460: 2457: 2452: 2448: 2440: 2426: 2423: 2418: 2414: 2406: 2405: 2404: 2402: 2383: 2380: 2375: 2371: 2364: 2342: 2339: 2336: 2332: 2309: 2306: 2303: 2299: 2290: 2286: 2282: 2277: 2275: 2271: 2267: 2262: 2260: 2256: 2252: 2248: 2244: 2240: 2236: 2220: 2216: 2209: 2206: 2203: 2197: 2194: 2174: 2171: 2168: 2160: 2156: 2152: 2136: 2133: 2129: 2123: 2120: 2114: 2105: 2101: 2085: 2082: 2079: 2075: 2069: 2065: 2062: 2055: 2050: 2044: 2041: 2035: 2014: 2011: 2008: 2004: 1998: 1995: 1989: 1980: 1976: 1972: 1967: 1965: 1961: 1945: 1942: 1939: 1935: 1929: 1926: 1920: 1910: 1908: 1904: 1896: 1894: 1877: 1874: 1871: 1848: 1845: 1842: 1839: 1836: 1833: 1830: 1803: 1799: 1791: 1788: 1781: 1777: 1773: 1770: 1766: 1758: 1757: 1756: 1735: 1731: 1723: 1720: 1717: 1712: 1708: 1695: 1691: 1683: 1680: 1675: 1671: 1663: 1662: 1661: 1659: 1655: 1651: 1647: 1642: 1640: 1636: 1635: 1629: 1625: 1607: 1603: 1580: 1576: 1567: 1562: 1548: 1528: 1525: 1522: 1519: 1516: 1496: 1476: 1456: 1436: 1416: 1413: 1410: 1405: 1401: 1380: 1360: 1351: 1349: 1348: 1343: 1339: 1335: 1331: 1308: 1304: 1296: 1293: 1286: 1282: 1278: 1275: 1271: 1263: 1262: 1261: 1240: 1236: 1228: 1225: 1220: 1216: 1208: 1207: 1206: 1204: 1200: 1196: 1193:for a given ( 1192: 1187: 1173: 1151: 1147: 1143: 1140: 1119: 1113: 1110: 1104: 1100: 1097: 1094: 1088: 1082: 1070: 1064: 1063: 1062: 1060: 1056: 1051: 1049: 1045: 1041: 1037: 1033: 1032: 1027: 1022: 1020: 1016: 1012: 1008: 989: 982: 978: 970: 967: 962: 958: 950: 949: 948: 933: 927: 924: 918: 909: 904: 902: 898: 879: 872: 868: 860: 857: 854: 851: 846: 842: 834: 833: 832: 830: 823: 806: 800: 797: 791: 782: 777: 775: 768: 761: 754: 746: 742: 737: 733: 729: 725: 722:Examples: If 720: 718: 714: 710: 706: 702: 698: 694: 690: 686: 682: 678: 677: 672: 668: 664: 663: 657: 655: 651: 650: 640: 633: 631: 617: 610: 606: 598: 595: 590: 587: 584: 580: 572: 571: 568: 566: 565: 548: 545: 542: 539: 535: 529: 526: 520: 510: 508: 504: 487: 481: 478: 472: 463: 458: 456: 455: 450: 446: 442: 439:for a given ( 438: 433: 431: 430: 425: 421: 417: 414:for a given ( 413: 405: 403: 401: 396: 394: 390: 389: 383: 381: 377: 373: 369: 365: 361: 357: 348: 341: 339: 325: 318: 314: 306: 303: 295: 289: 285: 277: 276: 273: 271: 267: 263: 244: 240: 234: 231: 225: 221: 218: 215: 209: 203: 196: 195: 194: 192: 191:Jacobi symbol 175: 169: 166: 160: 151: 146: 144: 140: 136: 132: 125: 121: 117: 98: 95: 92: 87: 83: 79: 76: 68: 64: 60: 52: 50: 48: 44: 40: 36: 32: 19: 7624:Pseudoprimes 7331:Transposable 7195:Narcissistic 7102:Digital root 7022:Super-Poulet 6982:Jordan–PĂłlya 6931:prime factor 6836:Noncototient 6803:Almost prime 6785:Superperfect 6760:Refactorable 6755:Quasiperfect 6730:Hyperperfect 6616: 6571:Pseudoprimes 6542:Wall–Sun–Sun 6477:Ordered Bell 6447:Fuss–Catalan 6359:non-centered 6309:Dodecahedral 6286:non-centered 6172:non-centered 6074:Wolstenholme 5819:× 2 ± 1 5816: 5815:Of the form 5782:Eighth power 5762:Fourth power 5664: 5645: 5626: 5607: 5554: 5526: 5522: 5516: 5507: 5503: 5497: 5485:. Retrieved 5476: 5467: 5463: 5457: 5432: 5428: 5419: 5400: 5396: 5390: 5381: 5377: 5364: 5337: 5333: 5327: 5292: 5288: 5278: 5233: 5229: 5219: 5192: 5188: 5164: 5141: 5104: 5065: 5008: 5004: 4945: 4941: 4939: 4927: 4923: 4919: 4917: 4830: 4818: 4814: 4810: 4804: 4800: 4796: 4794: 4786: 4780: 4776: 4772: 4768: 4764: 4760: 4756: 4746: 4739: 4735: 4731: 4730:) holds for 4725: 4721: 4717: 4715: 4708: 4696: 4691: 4689: 4671: 4665: 4661: 4655: 4651: 4647: 4641: 4630: 4551: 4547: 4543: 4541: 4536: 4528: 4526: 4523: 4503: 4499: 4493: 4489: 4485: 4483: 4478: 4474: 4467: 4463: 4459: 4457: 4441: 4432: 4428: 4424: 4416: 4412: 4408: 4404: 4402: 4397: 4393: 4391: 4386: 4382: 4378: 4374: 4372: 4369: 4364: 4356: 4355: 4345: 4341: 4337: 4335: 4324: 4320: 4316: 4314: 4303: 4157: 4155: 4150: 4107: 4008: 4006: 3871:Recall that 3870: 3838: 3831: 3827: 3823: 3819: 3813: 3809: 3805: 3801: 3793: 3789: 3748: 3744: 3740: 3736: 3732: 3728: 3724: 3722: 3715: 3711: 3707: 3703: 3697: 3691: 3689: 3681: 3674: 3672: 3661: 3542: 3540: 3535: 3529: 3527: 3508:extra strong 3507: 3503: 3499: 3495: 3403: 3374:extra strong 3373: 3371: 3356: 3352: 3348: 3344: 3342: 3337: 3335: 3320: 3316: 3312: 3310: 3302: 3296: 3292: 3288: 3281: 3274: 3272: 3267: 3263: 3259: 3255: 3251: 3247: 3243: 3239: 3235: 3228: 3221: 3214: 3207: 3200: 3193: 3186: 3179: 3174:= 22, 101100 3143: 3139: 3135: 3131: 3129: 3124: 3062: 3057: 3053: 3049: 3045: 3038: 2890: 2700: 2481: 2288: 2284: 2280: 2278: 2273: 2269: 2265: 2263: 2254: 2250: 2246: 2242: 2238: 2234: 2158: 2154: 2150: 2103: 2099: 2027:. Note that 1978: 1974: 1970: 1968: 1963: 1959: 1958:, so that ÎŽ( 1911: 1902: 1900: 1822: 1754: 1657: 1653: 1649: 1645: 1643: 1638: 1633: 1631: 1627: 1623: 1565: 1563: 1352: 1345: 1341: 1337: 1333: 1329: 1327: 1259: 1202: 1198: 1194: 1190: 1188: 1075:Now, factor 1074: 1058: 1054: 1052: 1047: 1043: 1039: 1035: 1029: 1024:We will see 1023: 1021:= −1. 1018: 1014: 1010: 1006: 1004: 907: 905: 900: 896: 894: 825: 821: 780: 778: 770: 763: 756: 749: 735: 731: 727: 723: 721: 716: 712: 708: 704: 700: 696: 692: 688: 684: 680: 674: 670: 666: 660: 658: 653: 647: 645: 634: 562: 511: 461: 459: 452: 448: 444: 440: 436: 434: 427: 423: 419: 415: 411: 409: 397: 386: 384: 375: 371: 367: 363: 359: 355: 353: 342: 269: 261: 259: 193:. We define 149: 147: 138: 134: 127: 123: 119: 112: 66: 62: 58: 56: 34: 30: 29: 7352:Extravagant 7347:Equidigital 7302:permutation 7261:Palindromic 7235:Automorphic 7133:Sum-product 7112:Sum-product 7067:Persistence 6962:ErdƑs–Woods 6884:Untouchable 6765:Semiperfect 6715:Hemiperfect 6376:Tesseractic 6314:Icosahedral 6294:Tetrahedral 6225:Dodecagonal 5926:Recursively 5797:Prime power 5772:Sixth power 5767:Fifth power 5747:Power of 10 5705:Classes of 5529:: 173–177. 5403:: 347–354. 4668:= −1. 4421:twin primes 4392:Therefore, 3836:) is true. 3402:. Then try 3170:= 11, 10110 2399:steps; see 1568:= −1, then 1564:We can set 1007:pseudoprime 779:First, let 776:= 10, etc. 400:Mathematica 358:hold, then 69:> 0 and 7613:Categories 7564:Graphemics 7437:Pernicious 7291:Undulating 7266:Pandigital 7240:Trimorphic 6841:Nontotient 6690:Arithmetic 6304:Octahedral 6205:Heptagonal 6195:Pentagonal 6180:Triangular 6021:SierpiƄski 5943:Jacobsthal 5742:Power of 3 5737:Power of 2 5510:: 155–157. 5302:2006.14425 5243:1903.06820 5060:Stan Wagon 4952:References 4423:. Such an 3957:, namely, 3166:= 10, 1011 1050:sequence. 1009:for this ( 855:6616217487 719:is prime. 567:) becomes 418:) pair is 366:prime. If 7321:Parasitic 7170:Factorion 7097:Digit sum 7089:Digit sum 6907:Fortunate 6894:Primorial 6808:Semiprime 6745:Practical 6710:Descartes 6705:Deficient 6695:Betrothed 6537:Wieferich 6366:Pentatope 6329:pyramidal 6220:Decagonal 6215:Nonagonal 6210:Octagonal 6200:Hexagonal 6059:Practical 6006:Congruent 5938:Fibonacci 5902:Loeschian 5666:MathWorld 5647:MathWorld 5628:MathWorld 5609:MathWorld 5531:CiteSeerX 5405:CiteSeerX 5342:CiteSeerX 5319:220055722 4867:≡ 4779:dividing 4592:≡ 4248:⋅ 4242:≡ 4223:− 4209:⋅ 4203:≡ 4056:≡ 4037:− 3853:± 3850:≠ 3796:= 5 (see 3620:≡ 3576:− 3479:− 3430:− 3162:= 5, 1010 2954:⋅ 2902:⋅ 2851:⋅ 2829:⋅ 2740:⋅ 2624:− 2562:⋅ 2381:⁡ 2207:− 2161:, we set 2083:− 2063:− 2012:− 1943:− 1846:− 1834:≤ 1823:for some 1789:≡ 1774:⋅ 1721:± 1718:≡ 1681:≡ 1526:⁡ 1520:⋅ 1411:− 1294:≡ 1279:⋅ 1226:≡ 1201:with GCD( 1144:⋅ 1101:− 1083:δ 968:≡ 858:≡ 596:≡ 543:− 445:composite 372:composite 304:≡ 290:δ 222:− 204:δ 93:− 39:composite 7393:Friedman 7326:Primeval 7271:Repdigit 7228:-related 7175:Kaprekar 7149:Meertens 7072:Additive 7059:dynamics 6967:Friendly 6879:Sociable 6869:Amicable 6680:Abundant 6660:dynamics 6482:Schröder 6472:Narayana 6442:Eulerian 6432:Delannoy 6427:Dedekind 6248:centered 6114:centered 6001:Amenable 5958:Narayana 5948:Leonardo 5844:Mersenne 5792:Powerful 5732:Achilles 5140:(1996). 5103:(2005). 5062:(2000). 4813:= 2 and 4771:− 4767:+ 1) | ( 4759:+ 1) | ( 4664:= 1 and 4502:= 1 and 4462:= 1 and 3747:so that 3158:= 4, 101 3154:= 2, 100 1656:) where 1186:is odd. 1038:, we do 824:) = 20, 689:probable 447:integer 65:, where 7566:related 7530:related 7494:related 7492:Sorting 7377:Vampire 7362:Harshad 7304:related 7276:Repunit 7190:Lychrel 7165:Dudeney 7017:StĂžrmer 7012:Sphenic 6997:Regular 6935:divisor 6874:Perfect 6770:Sublime 6740:Perfect 6467:Motzkin 6422:Catalan 5963:Padovan 5897:Leyland 5892:Idoneal 5887:Hilbert 5859:Woodall 5449:2689212 5270:1680879 5248:Bibcode 5211:2006210 5035:0583518 5027:2006406 4933:as the 4838:A099011 4836::  4703:in the 4700:A141137 4682:in the 4679:A005845 4516:in the 4513:A081264 4145:is the 4108:(Here, 3516:in the 3513:A217719 3365:in the 3362:A217255 3329:in the 3326:A217120 3291:, (mod 3150:= 1, 10 745:A006190 743::  376:usually 189:be the 7432:Odious 7357:Frugal 7311:Cyclic 7300:Digit- 7007:Smooth 6992:Pronic 6952:Cyclic 6929:Other 6902:Euclid 6552:Wilson 6526:Primes 6185:Square 6054:Polite 6016:Riesel 6011:Knödel 5973:Perrin 5854:Thabit 5839:Fermat 5829:Cullen 5752:Square 5720:Powers 5533:  5447:  5407:  5344:  5317:  5268:  5209:  5152:  5115:  5074:  5033:  5025:  4918:with ( 4853:  4431:+1 = ( 3826:, and 3731:, and 3696:) or ( 3502:, and 3357:strong 3351:, and 3338:strong 3319:, and 3287:, and 3266:, and 3227:, and 3123:, mod 3043:modulo 2287:, and 2279:Given 2253:, and 2098:. (If 1969:Given 1893:pair. 1541:, for 1342:strong 1166:where 685:likely 126:) and 111:, let 43:primes 7473:Prime 7468:Lucky 7457:sieve 7386:Other 7372:Smith 7252:Digit 7210:Happy 7185:Keith 7158:Other 7002:Rough 6972:Giuga 6437:Euler 6299:Cubic 5953:Lucas 5849:Proth 5487:5 May 5445:JSTOR 5374:(PDF) 5315:S2CID 5297:arXiv 5238:arXiv 5207:JSTOR 5185:(PDF) 5023:JSTOR 5001:(PDF) 4749:is a 4458:When 4149:; if 3343:When 3311:When 3136:which 1966:+ 1. 1332:< 1026:below 1017:= 3, 769:= 3, 762:= 1, 755:= 0, 738:s is 726:= 3, 695:that 693:prove 266:prime 264:is a 7427:Evil 7107:Self 7057:and 6947:Blum 6658:and 6462:Lobb 6417:Cake 6412:Bell 6162:Star 6069:Ulam 5968:Pell 5757:Cube 5489:2019 5150:ISBN 5113:ISBN 5072:ISBN 4834:OEIS 4705:OEIS 4684:OEIS 4518:OEIS 4321:n, Q 3810:only 3804:and 3751:and 3743:and 3708:both 3518:OEIS 3367:OEIS 3336:The 3331:OEIS 2324:and 2187:and 2102:and 1962:) = 1840:< 1622:are 1595:and 1469:and 1373:and 1338:P, Q 1203:n, D 1195:P, Q 1053:Let 1011:P, Q 897:P, Q 741:OEIS 707:and 441:P, Q 416:P, Q 148:Let 61:and 37:are 33:and 7545:Ban 6933:or 6452:Lah 5559:doi 5437:doi 5352:doi 5307:doi 5256:doi 5197:doi 5013:doi 4895:mod 4713:). 4603:mod 4542:If 4527:If 4342:any 4276:mod 4084:mod 4007:If 3839:If 3720:). 3684:n+1 3677:n+1 3634:mod 3541:If 3305:n+1 3284:n+1 3277:n+1 2891:If 2502:to 2372:log 2357:in 2241:or 1800:mod 1755:or 1732:mod 1692:mod 1644:An 1523:log 1350:). 1305:mod 1260:or 1237:mod 1066:... 1040:not 983:119 979:mod 963:120 928:119 901:not 869:mod 683:is 607:mod 512:If 420:any 370:is 364:not 362:is 356:not 315:mod 260:If 7615:: 5663:. 5644:. 5625:. 5606:. 5545:^ 5527:31 5525:. 5508:32 5506:. 5466:. 5443:. 5433:47 5431:. 5401:28 5399:. 5382:27 5380:. 5376:. 5350:. 5338:66 5336:. 5313:. 5305:. 5293:90 5291:. 5266:MR 5264:. 5254:. 5246:. 5234:70 5232:. 5228:. 5205:. 5193:35 5191:. 5187:. 5176:; 5172:; 5148:. 5144:. 5127:^ 5111:. 5099:; 5086:^ 5058:; 5043:^ 5031:MR 5029:. 5021:. 5009:35 5007:. 5003:. 4960:^ 4944:, 4922:, 4795:A 4755:2( 4716:A 4686:), 4646:a 4550:, 4520:). 4484:A 4450:. 4411:= 4333:. 4015:, 4004:. 3822:, 3792:= 3727:, 3687:. 3520:) 3498:, 3369:) 3347:, 3333:) 3315:, 3308:. 3280:, 3270:. 3262:, 3258:, 3254:, 3250:, 3246:, 3242:, 3232:44 3225:22 3220:, 3218:11 3213:, 3211:10 3206:, 3199:, 3192:, 3185:, 3127:. 3083:, 3060:. 2283:, 2261:. 2249:, 1652:, 1189:A 925:13 873:19 847:20 828:20 801:19 798:13 748:: 736:U' 703:, 435:A 410:A 382:. 145:. 137:, 122:, 49:. 5817:a 5698:e 5691:t 5684:v 5669:. 5650:. 5631:. 5612:. 5565:. 5561:: 5539:. 5491:. 5468:4 5451:. 5439:: 5413:. 5358:. 5354:: 5321:. 5309:: 5299:: 5272:. 5258:: 5250:: 5240:: 5213:. 5199:: 5158:. 5121:. 5080:. 5037:. 5015:: 4946:Q 4942:P 4930:n 4928:U 4924:Q 4920:P 4902:) 4899:n 4892:( 4886:) 4880:n 4877:2 4871:( 4862:n 4858:U 4821:n 4819:U 4815:Q 4811:P 4806:1 4801:n 4783:. 4781:n 4777:p 4773:p 4769:n 4765:p 4761:n 4757:p 4747:n 4740:n 4736:P 4732:Q 4727:5 4722:n 4710:1 4666:Q 4662:P 4657:5 4652:n 4635:) 4633:5 4631:( 4614:. 4610:) 4607:n 4600:( 4595:P 4589:) 4586:Q 4583:, 4580:P 4577:( 4572:n 4568:V 4552:Q 4548:n 4544:n 4537:n 4529:n 4504:Q 4500:P 4495:1 4490:n 4479:Q 4477:, 4475:P 4473:( 4470:n 4468:U 4464:Q 4460:P 4433:p 4429:n 4425:n 4417:p 4415:( 4413:p 4409:n 4405:n 4398:n 4394:k 4387:n 4383:n 4379:Q 4377:, 4375:P 4365:n 4357:k 4346:n 4338:n 4326:4 4317:n 4308:) 4306:4 4304:( 4287:. 4283:) 4280:n 4273:( 4267:) 4261:n 4258:Q 4252:( 4245:Q 4237:2 4233:/ 4229:) 4226:1 4220:n 4217:( 4213:Q 4206:Q 4198:2 4194:/ 4190:) 4187:1 4184:+ 4181:n 4178:( 4174:Q 4158:n 4151:n 4132:) 4126:n 4123:Q 4117:( 4104:. 4091:) 4088:n 4081:( 4075:) 4069:n 4066:Q 4060:( 4051:2 4047:/ 4043:) 4040:1 4034:n 4031:( 4027:Q 4009:n 3990:2 3986:/ 3982:) 3979:1 3976:+ 3973:n 3970:( 3966:Q 3945:Q 3923:1 3920:+ 3917:n 3913:U 3890:1 3887:+ 3884:n 3880:Q 3856:1 3847:Q 3833:3 3828:Q 3824:P 3820:D 3815:3 3806:Q 3802:P 3794:Q 3790:P 3775:) 3769:n 3766:D 3760:( 3749:D 3745:Q 3741:P 3737:Q 3733:Q 3729:P 3725:D 3717:2 3712:n 3704:n 3699:3 3693:2 3682:U 3675:V 3666:) 3664:3 3662:( 3645:. 3641:) 3638:n 3631:( 3626:Q 3623:2 3615:1 3612:+ 3609:n 3605:V 3579:1 3573:= 3569:) 3563:n 3560:D 3554:( 3543:n 3536:n 3531:2 3504:Q 3500:P 3496:D 3482:1 3476:= 3472:) 3466:n 3463:D 3457:( 3436:Q 3433:4 3425:2 3421:P 3417:= 3414:D 3404:P 3390:1 3387:= 3384:Q 3353:Q 3349:P 3345:D 3321:Q 3317:P 3313:D 3303:U 3298:2 3293:n 3289:Q 3282:V 3275:U 3268:Q 3264:Q 3260:Q 3256:Q 3252:Q 3248:Q 3244:Q 3240:Q 3236:V 3229:U 3222:U 3215:U 3208:U 3204:5 3201:U 3197:4 3194:U 3190:2 3187:U 3183:1 3180:U 3176:2 3172:2 3168:2 3164:2 3160:2 3156:2 3152:2 3148:2 3144:n 3140:U 3132:n 3125:n 3111:Q 3091:V 3071:U 3058:Q 3054:V 3050:U 3046:n 3039:n 3023:1 3020:+ 3017:k 3014:2 3010:V 2989:n 2986:+ 2981:k 2978:2 2974:V 2970:+ 2965:k 2962:2 2958:U 2951:P 2929:k 2926:2 2922:V 2918:+ 2913:k 2910:2 2906:U 2899:P 2887:. 2875:2 2871:/ 2867:) 2862:k 2859:2 2855:V 2848:P 2845:+ 2840:k 2837:2 2833:U 2826:D 2823:( 2820:= 2815:1 2812:+ 2809:k 2806:2 2802:V 2780:2 2776:/ 2772:) 2767:k 2764:2 2760:V 2756:+ 2751:k 2748:2 2744:U 2737:P 2734:( 2731:= 2726:1 2723:+ 2720:k 2717:2 2713:U 2697:. 2683:2 2677:2 2672:k 2668:U 2664:D 2661:+ 2656:2 2651:k 2647:V 2640:= 2635:k 2631:Q 2627:2 2619:2 2614:k 2610:V 2606:= 2601:k 2598:2 2594:V 2570:k 2566:V 2557:k 2553:U 2549:= 2544:k 2541:2 2537:U 2513:k 2510:2 2490:k 2467:1 2464:= 2461:P 2458:= 2453:1 2449:V 2427:1 2424:= 2419:1 2415:U 2387:) 2384:n 2376:2 2368:( 2365:O 2343:1 2340:+ 2337:n 2333:V 2310:1 2307:+ 2304:n 2300:U 2289:Q 2285:P 2281:D 2274:n 2270:n 2266:n 2255:Q 2251:P 2247:D 2243:Q 2239:P 2235:n 2221:4 2217:/ 2213:) 2210:D 2204:1 2201:( 2198:= 2195:Q 2175:1 2172:= 2169:P 2159:D 2155:D 2151:D 2137:0 2134:= 2130:) 2124:n 2121:D 2115:( 2104:n 2100:D 2086:1 2080:= 2076:) 2070:n 2066:k 2056:( 2051:) 2045:n 2042:k 2036:( 2015:1 2009:= 2005:) 1999:n 1996:D 1990:( 1979:D 1975:D 1971:n 1964:n 1960:n 1946:1 1940:= 1936:) 1930:n 1927:D 1921:( 1903:n 1881:) 1878:Q 1875:, 1872:P 1869:( 1849:1 1843:s 1837:r 1831:0 1807:) 1804:n 1797:( 1792:0 1782:r 1778:2 1771:d 1767:V 1739:) 1736:n 1729:( 1724:2 1713:d 1709:V 1699:) 1696:n 1689:( 1684:0 1676:d 1672:U 1658:Q 1654:Q 1650:P 1639:P 1634:P 1628:P 1624:P 1608:n 1604:V 1581:n 1577:U 1566:Q 1549:x 1529:x 1517:c 1497:x 1477:Q 1457:P 1437:c 1417:Q 1414:4 1406:2 1402:P 1381:Q 1361:P 1347:1 1334:s 1330:r 1312:) 1309:n 1302:( 1297:0 1287:r 1283:2 1276:d 1272:V 1244:) 1241:n 1234:( 1229:0 1221:d 1217:U 1199:n 1174:d 1152:s 1148:2 1141:d 1120:) 1114:n 1111:D 1105:( 1098:n 1095:= 1092:) 1089:n 1086:( 1059:P 1055:Q 1048:U 1044:n 1036:n 1031:2 1019:Q 1015:P 990:. 986:) 976:( 971:0 959:U 934:) 919:( 908:n 880:. 876:) 866:( 861:0 852:= 843:U 826:U 822:n 807:) 792:( 781:n 773:3 771:U 766:2 764:U 759:1 757:U 752:0 750:U 732:D 728:Q 724:P 717:n 713:n 709:Q 705:P 701:D 697:n 681:n 676:2 671:n 667:n 662:2 654:n 649:2 639:) 637:2 635:( 618:. 614:) 611:n 604:( 599:0 591:1 588:+ 585:n 581:U 564:1 549:, 546:1 540:= 536:) 530:n 527:D 521:( 488:) 482:n 479:D 473:( 462:D 454:1 449:n 429:1 424:n 388:1 368:n 360:n 347:) 345:1 343:( 326:. 322:) 319:n 312:( 307:0 299:) 296:n 293:( 286:U 270:Q 262:n 245:. 241:) 235:n 232:D 226:( 219:n 216:= 213:) 210:n 207:( 176:) 170:n 167:D 161:( 150:n 139:Q 135:P 133:( 130:k 128:V 124:Q 120:P 118:( 115:k 113:U 99:Q 96:4 88:2 84:P 80:= 77:D 67:P 63:Q 59:P 20:)

Index

Fibonacci pseudoprime
composite
primes
Lucas sequence
Lucas sequences
Jacobi symbol
prime
primality testing
1
Frobenius pseudoprime
Mathematica
1
1
strong pseudoprime
Baillie–PSW primality test
1
2
2
2
OEIS
A006190
below
2
1
Newton's method
John Selfridge
Lucas sequence § Other relations
modulo
2
A217120

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