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Primary pseudoperfect number

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290:, in which all elements of the solution set are prime. For instance, the prime factors of the primary pseudoperfect number 47058 form the solution set {2,3,11,23,31} to Znám's problem. However, the smaller primary pseudoperfect numbers 2, 6, 42, and 1806 do not correspond to solutions to Znám's problem in this way, as their sets of prime factors violate the requirement that no number in the set can equal one plus the product of the other numbers. Anne (1998) observes that there is exactly one solution set of this type that has 20: 2504: 479: 118: 329:
Primary pseudoperfect numbers were first investigated and named by Butske, Jaje, and Mayernik (2000). Using computational search techniques, they proved the remarkable result that for each positive
207: 321: + 1) is also primary pseudoperfect. For instance, 47058 is primary pseudoperfect, and 47059 is prime, so 47058 × 47059 = 2214502422 is also primary pseudoperfect. 606: 261: 599: 418: 23:
Graphical demonstration that 1 = 1/2 + 1/3 + 1/11 + 1/23 + 1/31 + 1/(2Ă—3Ă—11Ă—23Ă—31). Therefore the product, 47058, is primary pseudoperfect.
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Sondow, Jonathan; MacMillan, Kieren (2017), "Primary pseudoperfect numbers, arithmetic progressions, and the Erdős-Moser equation",
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It is unknown whether there are infinitely many primary pseudoperfect numbers, or whether there are any
2449: 2089: 2382: 2276: 2240: 1981: 1704: 1684: 1501: 1170: 958: 930: 287: 280: 2104: 1968: 1963: 1931: 1694: 1669: 1664: 1639: 1569: 1565: 1496: 1386: 1218: 1014: 983: 2503: 2507: 2261: 2256: 2170: 2144: 2042: 2021: 1793: 1674: 1624: 1546: 1516: 1456: 1223: 1203: 1134: 847: 537: 519: 401: 233: 1391: 570: 2401: 2346: 2200: 2175: 2149: 1926: 1604: 1599: 1526: 1506: 1491: 1213: 1195: 1114: 1104: 1089: 867: 852: 567: 44: 2437: 2230: 1816: 1788: 1778: 1770: 1654: 1619: 1614: 1581: 1275: 1238: 1129: 1124: 1119: 1109: 1081: 968: 920: 915: 872: 811: 529: 492: 393: 349: 273: 2413: 2302: 2235: 2161: 2084: 2058: 1876: 1589: 1446: 1381: 1351: 1341: 1336: 1002: 910: 857: 701: 641: 533: 2418: 2286: 2271: 2135: 2099: 2074: 1950: 1921: 1906: 1783: 1679: 1649: 1376: 1331: 1208: 806: 801: 796: 768: 753: 666: 651: 629: 616: 286:
The prime factors of primary pseudoperfect numbers sometimes may provide solutions to
2522: 2341: 2325: 2266: 2220: 1916: 1901: 1811: 1536: 1094: 963: 925: 882: 763: 748: 738: 696: 686: 661: 541: 32: 555: 2377: 2366: 2281: 2119: 2094: 2011: 1911: 1881: 1856: 1840: 1745: 1712: 1461: 1435: 1346: 1285: 862: 758: 691: 671: 646: 365: 124: 497: 254:, 1806, 47058, 2214502422, 52495396602, 8490421583559688410706771261086 (sequence 2336: 2211: 2016: 1480: 1371: 1326: 1321: 1071: 978: 877: 706: 681: 656: 251: 28: 19: 356:
6, 42, 78, 114, 150, 186, 222, as was observed by Sondow and MacMillan (2017).
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The first four of these numbers are one less than the corresponding numbers in
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Butske, William; Jaje, Lynda M.; Mayernik, Daniel R. (2000), "On the equation
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up to 8, there exists exactly one primary pseudoperfect number with precisely
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Anne, Premchand (1998), "Egyptian fractions and the inheritance problem",
2180: 2185: 1844: 474:{\displaystyle \scriptstyle \sum _{p|N}{\frac {1}{p}}+{\frac {1}{N}}=1} 405: 330: 397: 524: 113:{\displaystyle {\frac {1}{N}}+\sum _{p\,|\;\!N}{\frac {1}{p}}=1,} 2471: 2435: 2399: 2363: 2323: 1948: 1837: 1563: 1478: 1433: 1310: 1000: 947: 899: 833: 785: 723: 627: 588: 256: 216: = 2, this expression gives a representation for 481:, pseudoperfect numbers, and perfectly weighted graphs", 422: 344:
th known primary pseudoperfect number. Those with 2 ≤
421: 152: 56: 202:{\displaystyle 1+\sum _{p\,|\;\!N}{\frac {N}{p}}=N.} 2295: 2249: 2209: 2160: 2134: 2067: 2051: 2030: 1997: 1962: 1802: 1769: 1726: 1703: 1580: 1268: 1259: 1237: 1194: 1156: 1147: 1080: 1022: 1013: 473: 239:The eight known primary pseudoperfect numbers are 201: 143:is a primary pseudoperfect number if it satisfies 112: 174: 85: 224:. Therefore, each primary pseudoperfect number 600: 8: 212:Except for the primary pseudoperfect number 2468: 2432: 2396: 2360: 2320: 1994: 1959: 1945: 1834: 1577: 1560: 1475: 1430: 1307: 1265: 1153: 1019: 1010: 997: 944: 901:Possessing a specific set of other numbers 896: 830: 782: 720: 624: 607: 593: 585: 173: 84: 523: 496: 454: 441: 431: 427: 420: 180: 168: 167: 163: 151: 91: 79: 78: 74: 57: 55: 18: 340:(distinct) prime factors, namely, the 313:is one less than a prime number, then 7: 534:10.4169/amer.math.monthly.124.3.232 390:Mathematical Association of America 220:as the sum of distinct divisors of 309:If a primary pseudoperfect number 14: 511:The American Mathematical Monthly 302:that the same is true for larger 2502: 2110:Perfect digit-to-digit invariant 381:The College Mathematics Journal 283:primary pseudoperfect numbers. 123:where the sum is over only the 571:"Primary Pseudoperfect Number" 432: 169: 80: 1: 949:Expressible via specific sums 498:10.1090/S0025-5718-99-01088-1 556:Primary Pseudoperfect Number 41:primary pseudoperfect number 2038:Multiplicative digital root 2550: 484:Mathematics of Computation 2498: 2481: 2467: 2445: 2431: 2409: 2395: 2373: 2359: 2332: 2319: 2115:Perfect digital invariant 1958: 1944: 1852: 1833: 1690:Superior highly composite 1576: 1559: 1487: 1474: 1442: 1429: 1317: 1306: 1009: 996: 954: 943: 906: 895: 843: 829: 792: 781: 734: 719: 637: 623: 1728:Euler's totient function 1512:Euler–Jacobi pseudoprime 787:Other polynomial numbers 232: = 2) is also 1542:Somer–Lucas pseudoprime 1532:Lucas–Carmichael number 1367:Lazy caterer's sequence 294:primes in it, for each 1417:Wedderburn–Etherington 817:Lucky numbers of Euler 475: 354:arithmetic progression 203: 114: 31:, and particularly in 24: 1705:Prime omega functions 1522:Frobenius pseudoprime 1312:Combinatorial numbers 1181:Centered dodecahedral 974:Primary pseudoperfect 476: 204: 115: 22: 2164:-composition related 1964:Arithmetic functions 1566:Arithmetic functions 1502:Elliptic pseudoprime 1186:Centered icosahedral 1166:Centered tetrahedral 419: 270:Sylvester's sequence 150: 54: 43:if it satisfies the 2090:Kaprekar's constant 1610:Colossally abundant 1497:Catalan pseudoprime 1397:Schröder–Hipparchus 1176:Centered octahedral 1052:Centered heptagonal 1042:Centered pentagonal 1032:Centered triangular 632:and related numbers 272:, but then the two 2534:Egyptian fractions 2508:Mathematics portal 2450:Aronson's sequence 2196:Smarandache–Wellin 1953:-dependent numbers 1660:Primitive abundant 1547:Strong pseudoprime 1537:Perrin pseudoprime 1517:Fermat pseudoprime 1457:Wolstenholme prime 1281:Squared triangular 1067:Centered decagonal 1062:Centered nonagonal 1057:Centered octagonal 1047:Centered hexagonal 568:Weisstein, Eric W. 471: 470: 440: 348:≤ 8, when reduced 199: 179: 110: 90: 25: 2529:Integer sequences 2516: 2515: 2494: 2493: 2463: 2462: 2427: 2426: 2391: 2390: 2355: 2354: 2315: 2314: 2311: 2310: 2130: 2129: 1940: 1939: 1829: 1828: 1825: 1824: 1771:Aliquot sequences 1582:Divisor functions 1555: 1554: 1527:Lucas pseudoprime 1507:Euler pseudoprime 1492:Carmichael number 1470: 1469: 1425: 1424: 1302: 1301: 1298: 1297: 1294: 1293: 1255: 1254: 1143: 1142: 1100:Square triangular 992: 991: 939: 938: 891: 890: 825: 824: 777: 776: 715: 714: 462: 449: 423: 188: 159: 99: 70: 65: 45:Egyptian fraction 2541: 2506: 2469: 2438:Natural language 2433: 2397: 2365:Generated via a 2361: 2321: 2226:Digit-reassembly 2191:Self-descriptive 1995: 1960: 1946: 1897:Lucas–Carmichael 1887:Harmonic divisor 1835: 1761:Sparsely totient 1736:Highly cototient 1645:Multiply perfect 1635:Highly composite 1578: 1561: 1476: 1431: 1412:Telephone number 1308: 1266: 1247:Square pyramidal 1229:Stella octangula 1154: 1020: 1011: 1003:Figurate numbers 998: 945: 897: 831: 783: 721: 625: 609: 602: 595: 586: 581: 580: 544: 527: 501: 500: 480: 478: 477: 472: 463: 455: 450: 442: 439: 435: 408: 317: Ă— ( 259: 208: 206: 205: 200: 189: 181: 178: 172: 119: 117: 116: 111: 100: 92: 89: 83: 66: 58: 2549: 2548: 2544: 2543: 2542: 2540: 2539: 2538: 2519: 2518: 2517: 2512: 2490: 2486:Strobogrammatic 2477: 2459: 2441: 2423: 2405: 2387: 2369: 2351: 2328: 2307: 2291: 2250:Divisor-related 2245: 2205: 2156: 2126: 2063: 2047: 2026: 1993: 1966: 1954: 1936: 1848: 1847:related numbers 1821: 1798: 1765: 1756:Perfect totient 1722: 1699: 1630:Highly abundant 1572: 1551: 1483: 1466: 1438: 1421: 1407:Stirling second 1313: 1290: 1251: 1233: 1190: 1139: 1076: 1037:Centered square 1005: 988: 950: 935: 902: 887: 839: 838:defined numbers 821: 788: 773: 744:Double Mersenne 730: 711: 633: 619: 617:natural numbers 613: 566: 565: 552: 507: 417: 416: 414: 398:10.2307/2687685 377: 374: 362: 327: 255: 148: 147: 137: 52: 51: 17: 12: 11: 5: 2547: 2545: 2537: 2536: 2531: 2521: 2520: 2514: 2513: 2511: 2510: 2499: 2496: 2495: 2492: 2491: 2489: 2488: 2482: 2479: 2478: 2472: 2465: 2464: 2461: 2460: 2458: 2457: 2452: 2446: 2443: 2442: 2436: 2429: 2428: 2425: 2424: 2422: 2421: 2419:Sorting number 2416: 2414:Pancake number 2410: 2407: 2406: 2400: 2393: 2392: 2389: 2388: 2386: 2385: 2380: 2374: 2371: 2370: 2364: 2357: 2356: 2353: 2352: 2350: 2349: 2344: 2339: 2333: 2330: 2329: 2326:Binary numbers 2324: 2317: 2316: 2313: 2312: 2309: 2308: 2306: 2305: 2299: 2297: 2293: 2292: 2290: 2289: 2284: 2279: 2274: 2269: 2264: 2259: 2253: 2251: 2247: 2246: 2244: 2243: 2238: 2233: 2228: 2223: 2217: 2215: 2207: 2206: 2204: 2203: 2198: 2193: 2188: 2183: 2178: 2173: 2167: 2165: 2158: 2157: 2155: 2154: 2153: 2152: 2141: 2139: 2136:P-adic numbers 2132: 2131: 2128: 2127: 2125: 2124: 2123: 2122: 2112: 2107: 2102: 2097: 2092: 2087: 2082: 2077: 2071: 2069: 2065: 2064: 2062: 2061: 2055: 2053: 2052:Coding-related 2049: 2048: 2046: 2045: 2040: 2034: 2032: 2028: 2027: 2025: 2024: 2019: 2014: 2009: 2003: 2001: 1992: 1991: 1990: 1989: 1987:Multiplicative 1984: 1973: 1971: 1956: 1955: 1951:Numeral system 1949: 1942: 1941: 1938: 1937: 1935: 1934: 1929: 1924: 1919: 1914: 1909: 1904: 1899: 1894: 1889: 1884: 1879: 1874: 1869: 1864: 1859: 1853: 1850: 1849: 1838: 1831: 1830: 1827: 1826: 1823: 1822: 1820: 1819: 1814: 1808: 1806: 1800: 1799: 1797: 1796: 1791: 1786: 1781: 1775: 1773: 1767: 1766: 1764: 1763: 1758: 1753: 1748: 1743: 1741:Highly totient 1738: 1732: 1730: 1724: 1723: 1721: 1720: 1715: 1709: 1707: 1701: 1700: 1698: 1697: 1692: 1687: 1682: 1677: 1672: 1667: 1662: 1657: 1652: 1647: 1642: 1637: 1632: 1627: 1622: 1617: 1612: 1607: 1602: 1597: 1595:Almost perfect 1592: 1586: 1584: 1574: 1573: 1564: 1557: 1556: 1553: 1552: 1550: 1549: 1544: 1539: 1534: 1529: 1524: 1519: 1514: 1509: 1504: 1499: 1494: 1488: 1485: 1484: 1479: 1472: 1471: 1468: 1467: 1465: 1464: 1459: 1454: 1449: 1443: 1440: 1439: 1434: 1427: 1426: 1423: 1422: 1420: 1419: 1414: 1409: 1404: 1402:Stirling first 1399: 1394: 1389: 1384: 1379: 1374: 1369: 1364: 1359: 1354: 1349: 1344: 1339: 1334: 1329: 1324: 1318: 1315: 1314: 1311: 1304: 1303: 1300: 1299: 1296: 1295: 1292: 1291: 1289: 1288: 1283: 1278: 1272: 1270: 1263: 1257: 1256: 1253: 1252: 1250: 1249: 1243: 1241: 1235: 1234: 1232: 1231: 1226: 1221: 1216: 1211: 1206: 1200: 1198: 1192: 1191: 1189: 1188: 1183: 1178: 1173: 1168: 1162: 1160: 1151: 1145: 1144: 1141: 1140: 1138: 1137: 1132: 1127: 1122: 1117: 1112: 1107: 1102: 1097: 1092: 1086: 1084: 1078: 1077: 1075: 1074: 1069: 1064: 1059: 1054: 1049: 1044: 1039: 1034: 1028: 1026: 1017: 1007: 1006: 1001: 994: 993: 990: 989: 987: 986: 981: 976: 971: 966: 961: 955: 952: 951: 948: 941: 940: 937: 936: 934: 933: 928: 923: 918: 913: 907: 904: 903: 900: 893: 892: 889: 888: 886: 885: 880: 875: 870: 865: 860: 855: 850: 844: 841: 840: 834: 827: 826: 823: 822: 820: 819: 814: 809: 804: 799: 793: 790: 789: 786: 779: 778: 775: 774: 772: 771: 766: 761: 756: 751: 746: 741: 735: 732: 731: 724: 717: 716: 713: 712: 710: 709: 704: 699: 694: 689: 684: 679: 674: 669: 664: 659: 654: 649: 644: 638: 635: 634: 628: 621: 620: 614: 612: 611: 604: 597: 589: 583: 582: 563: 551: 550:External links 548: 547: 546: 518:(3): 232–240, 504: 503: 469: 466: 461: 458: 453: 448: 445: 438: 434: 430: 426: 411: 410: 373: 370: 369: 368: 361: 358: 352:288, form the 326: 323: 288:Znám's problem 266: 265: 210: 209: 198: 195: 192: 187: 184: 177: 171: 166: 162: 158: 155: 139:Equivalently, 136: 133: 125:prime divisors 121: 120: 109: 106: 103: 98: 95: 88: 82: 77: 73: 69: 64: 61: 16:Type of number 15: 13: 10: 9: 6: 4: 3: 2: 2546: 2535: 2532: 2530: 2527: 2526: 2524: 2509: 2505: 2501: 2500: 2497: 2487: 2484: 2483: 2480: 2475: 2470: 2466: 2456: 2453: 2451: 2448: 2447: 2444: 2439: 2434: 2430: 2420: 2417: 2415: 2412: 2411: 2408: 2403: 2398: 2394: 2384: 2381: 2379: 2376: 2375: 2372: 2368: 2362: 2358: 2348: 2345: 2343: 2340: 2338: 2335: 2334: 2331: 2327: 2322: 2318: 2304: 2301: 2300: 2298: 2294: 2288: 2285: 2283: 2280: 2278: 2277:Polydivisible 2275: 2273: 2270: 2268: 2265: 2263: 2260: 2258: 2255: 2254: 2252: 2248: 2242: 2239: 2237: 2234: 2232: 2229: 2227: 2224: 2222: 2219: 2218: 2216: 2213: 2208: 2202: 2199: 2197: 2194: 2192: 2189: 2187: 2184: 2182: 2179: 2177: 2174: 2172: 2169: 2168: 2166: 2163: 2159: 2151: 2148: 2147: 2146: 2143: 2142: 2140: 2137: 2133: 2121: 2118: 2117: 2116: 2113: 2111: 2108: 2106: 2103: 2101: 2098: 2096: 2093: 2091: 2088: 2086: 2083: 2081: 2078: 2076: 2073: 2072: 2070: 2066: 2060: 2057: 2056: 2054: 2050: 2044: 2041: 2039: 2036: 2035: 2033: 2031:Digit product 2029: 2023: 2020: 2018: 2015: 2013: 2010: 2008: 2005: 2004: 2002: 2000: 1996: 1988: 1985: 1983: 1980: 1979: 1978: 1975: 1974: 1972: 1970: 1965: 1961: 1957: 1952: 1947: 1943: 1933: 1930: 1928: 1925: 1923: 1920: 1918: 1915: 1913: 1910: 1908: 1905: 1903: 1900: 1898: 1895: 1893: 1890: 1888: 1885: 1883: 1880: 1878: 1875: 1873: 1870: 1868: 1867:ErdĹ‘s–Nicolas 1865: 1863: 1860: 1858: 1855: 1854: 1851: 1846: 1842: 1836: 1832: 1818: 1815: 1813: 1810: 1809: 1807: 1805: 1801: 1795: 1792: 1790: 1787: 1785: 1782: 1780: 1777: 1776: 1774: 1772: 1768: 1762: 1759: 1757: 1754: 1752: 1749: 1747: 1744: 1742: 1739: 1737: 1734: 1733: 1731: 1729: 1725: 1719: 1716: 1714: 1711: 1710: 1708: 1706: 1702: 1696: 1693: 1691: 1688: 1686: 1685:Superabundant 1683: 1681: 1678: 1676: 1673: 1671: 1668: 1666: 1663: 1661: 1658: 1656: 1653: 1651: 1648: 1646: 1643: 1641: 1638: 1636: 1633: 1631: 1628: 1626: 1623: 1621: 1618: 1616: 1613: 1611: 1608: 1606: 1603: 1601: 1598: 1596: 1593: 1591: 1588: 1587: 1585: 1583: 1579: 1575: 1571: 1567: 1562: 1558: 1548: 1545: 1543: 1540: 1538: 1535: 1533: 1530: 1528: 1525: 1523: 1520: 1518: 1515: 1513: 1510: 1508: 1505: 1503: 1500: 1498: 1495: 1493: 1490: 1489: 1486: 1482: 1477: 1473: 1463: 1460: 1458: 1455: 1453: 1450: 1448: 1445: 1444: 1441: 1437: 1432: 1428: 1418: 1415: 1413: 1410: 1408: 1405: 1403: 1400: 1398: 1395: 1393: 1390: 1388: 1385: 1383: 1380: 1378: 1375: 1373: 1370: 1368: 1365: 1363: 1360: 1358: 1355: 1353: 1350: 1348: 1345: 1343: 1340: 1338: 1335: 1333: 1330: 1328: 1325: 1323: 1320: 1319: 1316: 1309: 1305: 1287: 1284: 1282: 1279: 1277: 1274: 1273: 1271: 1267: 1264: 1262: 1261:4-dimensional 1258: 1248: 1245: 1244: 1242: 1240: 1236: 1230: 1227: 1225: 1222: 1220: 1217: 1215: 1212: 1210: 1207: 1205: 1202: 1201: 1199: 1197: 1193: 1187: 1184: 1182: 1179: 1177: 1174: 1172: 1171:Centered cube 1169: 1167: 1164: 1163: 1161: 1159: 1155: 1152: 1150: 1149:3-dimensional 1146: 1136: 1133: 1131: 1128: 1126: 1123: 1121: 1118: 1116: 1113: 1111: 1108: 1106: 1103: 1101: 1098: 1096: 1093: 1091: 1088: 1087: 1085: 1083: 1079: 1073: 1070: 1068: 1065: 1063: 1060: 1058: 1055: 1053: 1050: 1048: 1045: 1043: 1040: 1038: 1035: 1033: 1030: 1029: 1027: 1025: 1021: 1018: 1016: 1015:2-dimensional 1012: 1008: 1004: 999: 995: 985: 982: 980: 977: 975: 972: 970: 967: 965: 962: 960: 959:Nonhypotenuse 957: 956: 953: 946: 942: 932: 929: 927: 924: 922: 919: 917: 914: 912: 909: 908: 905: 898: 894: 884: 881: 879: 876: 874: 871: 869: 866: 864: 861: 859: 856: 854: 851: 849: 846: 845: 842: 837: 832: 828: 818: 815: 813: 810: 808: 805: 803: 800: 798: 795: 794: 791: 784: 780: 770: 767: 765: 762: 760: 757: 755: 752: 750: 747: 745: 742: 740: 737: 736: 733: 728: 722: 718: 708: 705: 703: 700: 698: 697:Perfect power 695: 693: 690: 688: 687:Seventh power 685: 683: 680: 678: 675: 673: 670: 668: 665: 663: 660: 658: 655: 653: 650: 648: 645: 643: 640: 639: 636: 631: 626: 622: 618: 610: 605: 603: 598: 596: 591: 590: 587: 578: 577: 572: 569: 564: 561: 557: 554: 553: 549: 543: 539: 535: 531: 526: 521: 517: 513: 512: 506: 505: 499: 494: 490: 486: 485: 467: 464: 459: 456: 451: 446: 443: 436: 428: 424: 413: 412: 407: 403: 399: 395: 391: 387: 383: 382: 376: 375: 371: 367: 364: 363: 359: 357: 355: 351: 347: 343: 339: 335: 332: 324: 322: 320: 316: 312: 307: 305: 301: 297: 293: 289: 284: 282: 277: 275: 271: 263: 258: 253: 249: 245: 242: 241: 240: 237: 235: 234:pseudoperfect 231: 227: 223: 219: 215: 196: 193: 190: 185: 182: 175: 164: 160: 156: 153: 146: 145: 144: 142: 134: 132: 130: 126: 107: 104: 101: 96: 93: 86: 75: 71: 67: 62: 59: 50: 49: 48: 46: 42: 38: 34: 33:number theory 30: 21: 2241:Transposable 2105:Narcissistic 2012:Digital root 1932:Super-Poulet 1892:Jordan–PĂłlya 1841:prime factor 1746:Noncototient 1713:Almost prime 1695:Superperfect 1670:Refactorable 1665:Quasiperfect 1640:Hyperperfect 1481:Pseudoprimes 1452:Wall–Sun–Sun 1387:Ordered Bell 1357:Fuss–Catalan 1269:non-centered 1219:Dodecahedral 1196:non-centered 1082:non-centered 984:Wolstenholme 973: 729:× 2 ± 1 726: 725:Of the form 692:Eighth power 672:Fourth power 574: 515: 509: 488: 482: 385: 379: 366:Giuga number 345: 341: 337: 333: 328: 318: 314: 310: 308: 303: 295: 291: 285: 278: 267: 238: 229: 225: 221: 217: 213: 211: 140: 138: 128: 122: 40: 36: 26: 2262:Extravagant 2257:Equidigital 2212:permutation 2171:Palindromic 2145:Automorphic 2043:Sum-product 2022:Sum-product 1977:Persistence 1872:ErdĹ‘s–Woods 1794:Untouchable 1675:Semiperfect 1625:Hemiperfect 1286:Tesseractic 1224:Icosahedral 1204:Tetrahedral 1135:Dodecagonal 836:Recursively 707:Prime power 682:Sixth power 677:Fifth power 657:Power of 10 615:Classes of 491:: 407–420, 392:: 296–300, 300:conjectures 29:mathematics 2523:Categories 2474:Graphemics 2347:Pernicious 2201:Undulating 2176:Pandigital 2150:Trimorphic 1751:Nontotient 1600:Arithmetic 1214:Octahedral 1115:Heptagonal 1105:Pentagonal 1090:Triangular 931:SierpiĹ„ski 853:Jacobsthal 652:Power of 3 647:Power of 2 560:PlanetMath 525:1812.06566 372:References 135:Properties 2231:Parasitic 2080:Factorion 2007:Digit sum 1999:Digit sum 1817:Fortunate 1804:Primorial 1718:Semiprime 1655:Practical 1620:Descartes 1615:Deficient 1605:Betrothed 1447:Wieferich 1276:Pentatope 1239:pyramidal 1130:Decagonal 1125:Nonagonal 1120:Octagonal 1110:Hexagonal 969:Practical 916:Congruent 848:Fibonacci 812:Loeschian 576:MathWorld 542:119618783 425:∑ 298:≤ 8, and 276:diverge. 274:sequences 161:∑ 72:∑ 47:equation 2303:Friedman 2236:Primeval 2181:Repdigit 2138:-related 2085:Kaprekar 2059:Meertens 1982:Additive 1969:dynamics 1877:Friendly 1789:Sociable 1779:Amicable 1590:Abundant 1570:dynamics 1392:Schröder 1382:Narayana 1352:Eulerian 1342:Delannoy 1337:Dedekind 1158:centered 1024:centered 911:Amenable 868:Narayana 858:Leonardo 754:Mersenne 702:Powerful 642:Achilles 360:See also 228:(except 2476:related 2440:related 2404:related 2402:Sorting 2287:Vampire 2272:Harshad 2214:related 2186:Repunit 2100:Lychrel 2075:Dudeney 1927:Størmer 1922:Sphenic 1907:Regular 1845:divisor 1784:Perfect 1680:Sublime 1650:Perfect 1377:Motzkin 1332:Catalan 873:Padovan 807:Leyland 802:Idoneal 797:Hilbert 769:Woodall 406:2687685 331:integer 325:History 260:in the 257:A054377 2342:Odious 2267:Frugal 2221:Cyclic 2210:Digit- 1917:Smooth 1902:Pronic 1862:Cyclic 1839:Other 1812:Euclid 1462:Wilson 1436:Primes 1095:Square 964:Polite 926:Riesel 921:Knödel 883:Perrin 764:Thabit 749:Fermat 739:Cullen 662:Square 630:Powers 540:  404:  350:modulo 2383:Prime 2378:Lucky 2367:sieve 2296:Other 2282:Smith 2162:Digit 2120:Happy 2095:Keith 2068:Other 1912:Rough 1882:Giuga 1347:Euler 1209:Cubic 863:Lucas 759:Proth 538:S2CID 520:arXiv 402:JSTOR 388:(4), 39:is a 2337:Evil 2017:Self 1967:and 1857:Blum 1568:and 1372:Lobb 1327:Cake 1322:Bell 1072:Star 979:Ulam 878:Pell 667:Cube 262:OEIS 2455:Ban 1843:or 1362:Lah 558:at 530:doi 516:124 493:doi 394:doi 281:odd 127:of 27:In 2525:: 573:. 536:, 528:, 514:, 489:69 487:, 400:, 386:29 384:, 306:. 264:). 252:42 250:, 246:, 236:. 131:. 35:, 727:a 608:e 601:t 594:v 579:. 562:. 545:. 532:: 522:: 502:. 495:: 468:1 465:= 460:N 457:1 452:+ 447:p 444:1 437:N 433:| 429:p 409:. 396:: 346:r 342:r 338:r 334:r 319:N 315:N 311:N 304:k 296:k 292:k 248:6 244:2 230:N 226:N 222:N 218:N 214:N 197:. 194:N 191:= 186:p 183:N 176:N 170:| 165:p 157:+ 154:1 141:N 129:N 108:, 105:1 102:= 97:p 94:1 87:N 81:| 76:p 68:+ 63:N 60:1 37:N

Index


mathematics
number theory
Egyptian fraction
prime divisors
pseudoperfect
2
6
42
A054377
OEIS
Sylvester's sequence
sequences
odd
Znám's problem
conjectures
integer
modulo
arithmetic progression
Giuga number
The College Mathematics Journal
Mathematical Association of America
doi
10.2307/2687685
JSTOR
2687685
Mathematics of Computation
doi
10.1090/S0025-5718-99-01088-1
The American Mathematical Monthly

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