Knowledge (XXG)

Vampire number

Source đź“ť

3118: 39:, that can be factored into two natural numbers each with half as many digits as the original number, where the two factors contain precisely all the digits of the original number, in any order, counting multiplicity. The two factors cannot both have trailing zeroes. The first vampire number is 1260 = 21 Ă— 60. 924:
However, 126000 (which can be expressed as 21 Ă— 6000 or 210 Ă— 600) is not a vampire number, since although 126000 = 21 Ă— 6000 and the digits (216000) are a permutation of the original number, the two factors 21 and 6000 do not have the correct number of digits. Furthermore, although 126000 = 210 Ă—
1038:
is 10392BA45768 = 105628 Ă— BA3974, where A means ten and B means eleven. Another example in the same base is a vampire number with three fangs, 572164B9A830 = 8752 Ă— 9346 Ă— A0B1. An example with four fangs is 3715A6B89420 = 763 Ă— 824 Ă— 905 Ă— B1A. In these examples, all 12 digits are used exactly
710: 967:
1260, 1395, 1435, 1530, 1827, 2187, 6880, 102510, 104260, 105210, 105264, 105750, 108135, 110758, 115672, 116725, 117067, 118440, 120600, 123354, 124483, 125248, 125433, 125460, 125500, ... (sequence
921:
1260 is a vampire number, with 21 and 60 as fangs, since 21 Ă— 60 = 1260 and the digits of the concatenation of the two factors (2160) are a permutation of the digits of the original number (1260).
171: 406: 331: 1220: 441: 495: 468: 737: 518: 88: 821: 797: 777: 757: 562: 542: 254: 234: 214: 194: 65: 566: 3142: 974: 1213: 2020: 1206: 2015: 2030: 2010: 1172: 1128: 2723: 2303: 997:
A vampire number can have multiple distinct pairs of fangs. The first of infinitely many vampire numbers with 2 pairs of fangs:
2025: 2809: 2125: 2475: 1794: 1587: 2510: 2480: 2155: 2145: 2651: 2065: 1799: 1779: 2341: 2505: 96: 2600: 2223: 1980: 1789: 1771: 1665: 1655: 1645: 2485: 1025:
24959017348650 = 2947050 Ă— 8469153 = 2949705 Ă— 8461530 = 4125870 Ă— 6049395 = 4129587 Ă— 6043950 = 4230765 Ă— 5899410
337: 262: 2728: 2273: 1894: 1680: 1675: 1670: 1660: 1637: 1107: 1713: 17: 1970: 2839: 2804: 2590: 2500: 2374: 2349: 2258: 2248: 1860: 1842: 1762: 3099: 2369: 2243: 1874: 1650: 1430: 1357: 2354: 2208: 2135: 1290: 3063: 2703: 2996: 2890: 2854: 2595: 2318: 2298: 2115: 1784: 1572: 1544: 827: 2718: 2582: 2577: 2545: 2308: 2283: 2278: 2253: 2183: 2179: 2110: 2000: 1832: 1628: 1597: 3117: 3121: 2875: 2870: 2784: 2758: 2656: 2635: 2407: 2288: 2238: 2160: 2130: 2070: 1837: 1817: 1748: 1461: 414: 2005: 1163: 1145: 981:
There are many known sequences of infinitely many vampire numbers following a pattern, such as:
3015: 2960: 2814: 2789: 2763: 2540: 2218: 2213: 2140: 2120: 2105: 1827: 1809: 1728: 1718: 1703: 1481: 1466: 1124: 1069: 1017:
16758243290880 = 1982736 Ă— 8452080 = 2123856 Ă— 7890480 = 2751840 Ă— 6089832 = 2817360 Ă— 5948208
3051: 2844: 2430: 2402: 2392: 2384: 2268: 2233: 2228: 2195: 1889: 1852: 1743: 1738: 1733: 1723: 1695: 1582: 1534: 1529: 1486: 1425: 29: 473: 446: 3027: 2916: 2849: 2775: 2698: 2672: 2490: 2203: 2060: 1995: 1965: 1955: 1950: 1616: 1524: 1471: 1315: 1255: 1048: 1034:
Vampire numbers also exist for bases other than base 10. For example, a vampire number in
36: 1184: 719: 500: 70: 3032: 2885: 2749: 2713: 2688: 2564: 2535: 2520: 2397: 2293: 2263: 1990: 1945: 1822: 1420: 1415: 1410: 1382: 1367: 1280: 1265: 1243: 1230: 834:
group sci.math, and the article he later wrote was published in chapter 30 of his book
806: 782: 762: 742: 547: 527: 239: 219: 199: 179: 50: 32: 3136: 2955: 2939: 2880: 2834: 2530: 2515: 2425: 2150: 1708: 1577: 1539: 1496: 1377: 1362: 1352: 1310: 1300: 1275: 521: 705:{\displaystyle ({a_{k}}{a_{k-1}}...{a_{2}}{a_{1}}{b_{k}}{b_{k-1}}...{b_{2}}{b_{1}})} 2991: 2980: 2895: 2733: 2708: 2625: 2525: 2495: 2470: 2454: 2359: 2326: 2075: 2049: 1960: 1899: 1476: 1372: 1305: 1285: 1260: 1072: 2950: 2825: 2630: 2094: 1985: 1940: 1935: 1685: 1592: 1491: 1320: 1295: 1270: 1180: 713: 3087: 3068: 2364: 1975: 1035: 1198: 2693: 2620: 2612: 2417: 2331: 1449: 1077: 989:
Al Sweigart calculated all the vampire numbers that have at most 10 digits.
2794: 2799: 2458: 831: 1094: 196:
is a vampire number if and only if there exist two natural numbers
3085: 3049: 3013: 2977: 2937: 2562: 2451: 2177: 2092: 2047: 1924: 1614: 1561: 1513: 1447: 1399: 1337: 1241: 1202: 985:
1530 = 30 Ă— 51, 150300 = 300 Ă— 501, 15003000 = 3000 Ă— 5001, ...
969: 826:
Vampire numbers were first described in a 1994 post by
809: 785: 765: 745: 722: 569: 550: 530: 503: 476: 449: 417: 340: 265: 242: 222: 202: 182: 99: 73: 53: 925:
600, both factors 210 and 600 have trailing zeroes.
2909: 2863: 2823: 2774: 2748: 2681: 2665: 2644: 2611: 2576: 2416: 2383: 2340: 2317: 2194: 1882: 1873: 1851: 1808: 1770: 1761: 1694: 1636: 1627: 1108:
Pickover's original post describing vampire numbers
1009:13078260 = 1620 Ă— 8073 = 1863 Ă— 7020 = 2070 Ă— 6318 815: 791: 771: 751: 731: 704: 556: 536: 512: 489: 462: 435: 400: 325: 248: 228: 208: 188: 165: 82: 59: 166:{\displaystyle N={n_{2k}}{n_{2k-1}}...{n_{1}}} 1214: 8: 401:{\displaystyle B={b_{k}}{b_{k-1}}...{b_{1}}} 326:{\displaystyle A={a_{k}}{a_{k-1}}...{a_{1}}} 3082: 3046: 3010: 2974: 2934: 2608: 2573: 2559: 2448: 2191: 2174: 2089: 2044: 1921: 1879: 1767: 1633: 1624: 1611: 1558: 1515:Possessing a specific set of other numbers 1510: 1444: 1396: 1334: 1238: 1221: 1207: 1199: 808: 784: 764: 744: 721: 692: 687: 680: 675: 653: 648: 641: 636: 629: 624: 617: 612: 590: 585: 578: 573: 568: 549: 529: 502: 481: 475: 454: 448: 416: 391: 386: 364: 359: 352: 347: 339: 316: 311: 289: 284: 277: 272: 264: 241: 221: 201: 181: 156: 151: 126: 121: 111: 106: 98: 72: 52: 845: 1060: 7: 963:The sequence of vampire numbers is: 928:The first few vampire numbers are: 856:Count of vampire numbers of length 14: 1021:The first with 5 pairs of fangs: 1013:The first with 4 pairs of fangs: 1005:The first with 3 pairs of fangs: 3143:Base-dependent integer sequences 3116: 2724:Perfect digit-to-digit invariant 1119:Pickover, Clifford A. (1995). 1001:125460 = 204 Ă— 615 = 246 Ă— 510 699: 570: 1: 1563:Expressible via specific sums 1171:Grime, James; Copeland, Ed. 1146:"Vampire Numbers Visualized" 2652:Multiplicative digital root 497:are not both zero, and the 436:{\displaystyle A\times B=N} 3159: 1165:Vampire Numbers Visualized 3112: 3095: 3081: 3059: 3045: 3023: 3009: 2987: 2973: 2946: 2933: 2729:Perfect digital invariant 2572: 2558: 2466: 2447: 2304:Superior highly composite 2190: 2173: 2101: 2088: 2056: 2043: 1931: 1920: 1623: 1610: 1568: 1557: 1520: 1509: 1457: 1443: 1406: 1395: 1348: 1333: 1251: 1237: 67:be a natural number with 2342:Euler's totient function 2126:Euler–Jacobi pseudoprime 1401:Other polynomial numbers 18:recreational mathematics 2156:Somer–Lucas pseudoprime 2146:Lucas–Carmichael number 1981:Lazy caterer's sequence 35:with an even number of 2031:Wedderburn–Etherington 1431:Lucky numbers of Euler 817: 793: 773: 753: 733: 706: 558: 538: 514: 491: 464: 437: 402: 327: 250: 230: 210: 190: 167: 84: 61: 2319:Prime omega functions 2136:Frobenius pseudoprime 1926:Combinatorial numbers 1795:Centered dodecahedral 1588:Primary pseudoperfect 818: 794: 774: 754: 734: 707: 559: 539: 515: 492: 490:{\displaystyle b_{1}} 465: 463:{\displaystyle a_{1}} 438: 403: 328: 251: 231: 211: 191: 168: 85: 62: 2778:-composition related 2578:Arithmetic functions 2180:Arithmetic functions 2116:Elliptic pseudoprime 1800:Centered icosahedral 1780:Centered tetrahedral 828:Clifford A. Pickover 807: 783: 763: 743: 720: 567: 548: 528: 501: 474: 447: 415: 338: 263: 240: 220: 200: 180: 97: 71: 51: 2704:Kaprekar's constant 2224:Colossally abundant 2111:Catalan pseudoprime 2011:Schröder–Hipparchus 1790:Centered octahedral 1666:Centered heptagonal 1656:Centered pentagonal 1646:Centered triangular 1246:and related numbers 993:Multiple fang pairs 847: 26:true vampire number 3122:Mathematics portal 3064:Aronson's sequence 2810:Smarandache–Wellin 2567:-dependent numbers 2274:Primitive abundant 2161:Strong pseudoprime 2151:Perrin pseudoprime 2131:Fermat pseudoprime 2071:Wolstenholme prime 1895:Squared triangular 1681:Centered decagonal 1676:Centered nonagonal 1671:Centered octagonal 1661:Centered hexagonal 1093:Andersen, Jens K. 1070:Weisstein, Eric W. 959:105210 = 210 Ă— 501 956:104260 = 260 Ă— 401 953:102510 = 201 Ă— 510 846: 813: 789: 769: 759:. The two numbers 749: 732:{\displaystyle 2k} 729: 702: 554: 534: 513:{\displaystyle 2k} 510: 487: 460: 433: 398: 323: 246: 226: 206: 186: 163: 83:{\displaystyle 2k} 80: 57: 3130: 3129: 3108: 3107: 3077: 3076: 3041: 3040: 3005: 3004: 2969: 2968: 2929: 2928: 2925: 2924: 2744: 2743: 2554: 2553: 2443: 2442: 2439: 2438: 2385:Aliquot sequences 2196:Divisor functions 2169: 2168: 2141:Lucas pseudoprime 2121:Euler pseudoprime 2106:Carmichael number 2084: 2083: 2039: 2038: 1916: 1915: 1912: 1911: 1908: 1907: 1869: 1868: 1757: 1756: 1714:Square triangular 1606: 1605: 1553: 1552: 1505: 1504: 1439: 1438: 1391: 1390: 1329: 1328: 1173:"Vampire numbers" 1095:"Vampire numbers" 1073:"Vampire Numbers" 919: 918: 816:{\displaystyle N} 792:{\displaystyle B} 772:{\displaystyle A} 752:{\displaystyle N} 557:{\displaystyle B} 537:{\displaystyle A} 249:{\displaystyle k} 229:{\displaystyle B} 209:{\displaystyle A} 189:{\displaystyle N} 60:{\displaystyle N} 3150: 3120: 3083: 3052:Natural language 3047: 3011: 2979:Generated via a 2975: 2935: 2840:Digit-reassembly 2805:Self-descriptive 2609: 2574: 2560: 2511:Lucas–Carmichael 2501:Harmonic divisor 2449: 2375:Sparsely totient 2350:Highly cototient 2259:Multiply perfect 2249:Highly composite 2192: 2175: 2090: 2045: 2026:Telephone number 1922: 1880: 1861:Square pyramidal 1843:Stella octangula 1768: 1634: 1625: 1617:Figurate numbers 1612: 1559: 1511: 1445: 1397: 1335: 1239: 1223: 1216: 1209: 1200: 1195: 1193: 1192: 1183:. Archived from 1150: 1149: 1141: 1135: 1134: 1121:Keys to Infinity 1116: 1110: 1105: 1099: 1098: 1090: 1084: 1083: 1082: 1065: 972: 848: 836:Keys to Infinity 822: 820: 819: 814: 798: 796: 795: 790: 778: 776: 775: 770: 758: 756: 755: 750: 738: 736: 735: 730: 711: 709: 708: 703: 698: 697: 696: 686: 685: 684: 665: 664: 663: 647: 646: 645: 635: 634: 633: 623: 622: 621: 602: 601: 600: 584: 583: 582: 563: 561: 560: 555: 543: 541: 540: 535: 519: 517: 516: 511: 496: 494: 493: 488: 486: 485: 469: 467: 466: 461: 459: 458: 442: 440: 439: 434: 407: 405: 404: 399: 397: 396: 395: 376: 375: 374: 358: 357: 356: 332: 330: 329: 324: 322: 321: 320: 301: 300: 299: 283: 282: 281: 255: 253: 252: 247: 235: 233: 232: 227: 215: 213: 212: 207: 195: 193: 192: 187: 172: 170: 169: 164: 162: 161: 160: 141: 140: 139: 120: 119: 118: 89: 87: 86: 81: 66: 64: 63: 58: 3158: 3157: 3153: 3152: 3151: 3149: 3148: 3147: 3133: 3132: 3131: 3126: 3104: 3100:Strobogrammatic 3091: 3073: 3055: 3037: 3019: 3001: 2983: 2965: 2942: 2921: 2905: 2864:Divisor-related 2859: 2819: 2770: 2740: 2677: 2661: 2640: 2607: 2580: 2568: 2550: 2462: 2461:related numbers 2435: 2412: 2379: 2370:Perfect totient 2336: 2313: 2244:Highly abundant 2186: 2165: 2097: 2080: 2052: 2035: 2021:Stirling second 1927: 1904: 1865: 1847: 1804: 1753: 1690: 1651:Centered square 1619: 1602: 1564: 1549: 1516: 1501: 1453: 1452:defined numbers 1435: 1402: 1387: 1358:Double Mersenne 1344: 1325: 1247: 1233: 1231:natural numbers 1227: 1190: 1188: 1170: 1159: 1154: 1153: 1143: 1142: 1138: 1131: 1118: 1117: 1113: 1106: 1102: 1092: 1091: 1087: 1068: 1067: 1066: 1062: 1057: 1049:Friedman number 1045: 1032: 995: 968: 844: 805: 804: 799:are called the 781: 780: 761: 760: 741: 740: 718: 717: 688: 676: 649: 637: 625: 613: 586: 574: 565: 564: 546: 545: 526: 525: 499: 498: 477: 472: 471: 450: 445: 444: 413: 412: 387: 360: 348: 336: 335: 312: 285: 273: 261: 260: 238: 237: 218: 217: 198: 197: 178: 177: 152: 122: 107: 95: 94: 69: 68: 49: 48: 45: 12: 11: 5: 3156: 3154: 3146: 3145: 3135: 3134: 3128: 3127: 3125: 3124: 3113: 3110: 3109: 3106: 3105: 3103: 3102: 3096: 3093: 3092: 3086: 3079: 3078: 3075: 3074: 3072: 3071: 3066: 3060: 3057: 3056: 3050: 3043: 3042: 3039: 3038: 3036: 3035: 3033:Sorting number 3030: 3028:Pancake number 3024: 3021: 3020: 3014: 3007: 3006: 3003: 3002: 3000: 2999: 2994: 2988: 2985: 2984: 2978: 2971: 2970: 2967: 2966: 2964: 2963: 2958: 2953: 2947: 2944: 2943: 2940:Binary numbers 2938: 2931: 2930: 2927: 2926: 2923: 2922: 2920: 2919: 2913: 2911: 2907: 2906: 2904: 2903: 2898: 2893: 2888: 2883: 2878: 2873: 2867: 2865: 2861: 2860: 2858: 2857: 2852: 2847: 2842: 2837: 2831: 2829: 2821: 2820: 2818: 2817: 2812: 2807: 2802: 2797: 2792: 2787: 2781: 2779: 2772: 2771: 2769: 2768: 2767: 2766: 2755: 2753: 2750:P-adic numbers 2746: 2745: 2742: 2741: 2739: 2738: 2737: 2736: 2726: 2721: 2716: 2711: 2706: 2701: 2696: 2691: 2685: 2683: 2679: 2678: 2676: 2675: 2669: 2667: 2666:Coding-related 2663: 2662: 2660: 2659: 2654: 2648: 2646: 2642: 2641: 2639: 2638: 2633: 2628: 2623: 2617: 2615: 2606: 2605: 2604: 2603: 2601:Multiplicative 2598: 2587: 2585: 2570: 2569: 2565:Numeral system 2563: 2556: 2555: 2552: 2551: 2549: 2548: 2543: 2538: 2533: 2528: 2523: 2518: 2513: 2508: 2503: 2498: 2493: 2488: 2483: 2478: 2473: 2467: 2464: 2463: 2452: 2445: 2444: 2441: 2440: 2437: 2436: 2434: 2433: 2428: 2422: 2420: 2414: 2413: 2411: 2410: 2405: 2400: 2395: 2389: 2387: 2381: 2380: 2378: 2377: 2372: 2367: 2362: 2357: 2355:Highly totient 2352: 2346: 2344: 2338: 2337: 2335: 2334: 2329: 2323: 2321: 2315: 2314: 2312: 2311: 2306: 2301: 2296: 2291: 2286: 2281: 2276: 2271: 2266: 2261: 2256: 2251: 2246: 2241: 2236: 2231: 2226: 2221: 2216: 2211: 2209:Almost perfect 2206: 2200: 2198: 2188: 2187: 2178: 2171: 2170: 2167: 2166: 2164: 2163: 2158: 2153: 2148: 2143: 2138: 2133: 2128: 2123: 2118: 2113: 2108: 2102: 2099: 2098: 2093: 2086: 2085: 2082: 2081: 2079: 2078: 2073: 2068: 2063: 2057: 2054: 2053: 2048: 2041: 2040: 2037: 2036: 2034: 2033: 2028: 2023: 2018: 2016:Stirling first 2013: 2008: 2003: 1998: 1993: 1988: 1983: 1978: 1973: 1968: 1963: 1958: 1953: 1948: 1943: 1938: 1932: 1929: 1928: 1925: 1918: 1917: 1914: 1913: 1910: 1909: 1906: 1905: 1903: 1902: 1897: 1892: 1886: 1884: 1877: 1871: 1870: 1867: 1866: 1864: 1863: 1857: 1855: 1849: 1848: 1846: 1845: 1840: 1835: 1830: 1825: 1820: 1814: 1812: 1806: 1805: 1803: 1802: 1797: 1792: 1787: 1782: 1776: 1774: 1765: 1759: 1758: 1755: 1754: 1752: 1751: 1746: 1741: 1736: 1731: 1726: 1721: 1716: 1711: 1706: 1700: 1698: 1692: 1691: 1689: 1688: 1683: 1678: 1673: 1668: 1663: 1658: 1653: 1648: 1642: 1640: 1631: 1621: 1620: 1615: 1608: 1607: 1604: 1603: 1601: 1600: 1595: 1590: 1585: 1580: 1575: 1569: 1566: 1565: 1562: 1555: 1554: 1551: 1550: 1548: 1547: 1542: 1537: 1532: 1527: 1521: 1518: 1517: 1514: 1507: 1506: 1503: 1502: 1500: 1499: 1494: 1489: 1484: 1479: 1474: 1469: 1464: 1458: 1455: 1454: 1448: 1441: 1440: 1437: 1436: 1434: 1433: 1428: 1423: 1418: 1413: 1407: 1404: 1403: 1400: 1393: 1392: 1389: 1388: 1386: 1385: 1380: 1375: 1370: 1365: 1360: 1355: 1349: 1346: 1345: 1338: 1331: 1330: 1327: 1326: 1324: 1323: 1318: 1313: 1308: 1303: 1298: 1293: 1288: 1283: 1278: 1273: 1268: 1263: 1258: 1252: 1249: 1248: 1242: 1235: 1234: 1228: 1226: 1225: 1218: 1211: 1203: 1197: 1196: 1168: 1162:Sweigart, Al. 1158: 1157:External links 1155: 1152: 1151: 1144:Sweigart, Al. 1136: 1129: 1111: 1100: 1085: 1059: 1058: 1056: 1053: 1052: 1051: 1044: 1041: 1031: 1028: 1027: 1026: 1019: 1018: 1011: 1010: 1003: 1002: 994: 991: 987: 986: 979: 978: 961: 960: 957: 954: 951: 950:6880 = 80 Ă— 86 948: 947:2187 = 27 Ă— 81 945: 944:1827 = 21 Ă— 87 942: 941:1530 = 30 Ă— 51 939: 938:1435 = 35 Ă— 41 936: 935:1395 = 15 Ă— 93 933: 932:1260 = 21 Ă— 60 917: 916: 913: 909: 908: 905: 901: 900: 897: 893: 892: 889: 885: 884: 881: 877: 876: 873: 869: 868: 865: 861: 860: 854: 843: 840: 812: 788: 768: 748: 728: 725: 701: 695: 691: 683: 679: 674: 671: 668: 662: 659: 656: 652: 644: 640: 632: 628: 620: 616: 611: 608: 605: 599: 596: 593: 589: 581: 577: 572: 553: 533: 520:digits of the 509: 506: 484: 480: 457: 453: 432: 429: 426: 423: 420: 409: 408: 394: 390: 385: 382: 379: 373: 370: 367: 363: 355: 351: 346: 343: 333: 319: 315: 310: 307: 304: 298: 295: 292: 288: 280: 276: 271: 268: 245: 225: 205: 185: 174: 173: 159: 155: 150: 147: 144: 138: 135: 132: 129: 125: 117: 114: 110: 105: 102: 79: 76: 56: 44: 41: 33:natural number 22:vampire number 13: 10: 9: 6: 4: 3: 2: 3155: 3144: 3141: 3140: 3138: 3123: 3119: 3115: 3114: 3111: 3101: 3098: 3097: 3094: 3089: 3084: 3080: 3070: 3067: 3065: 3062: 3061: 3058: 3053: 3048: 3044: 3034: 3031: 3029: 3026: 3025: 3022: 3017: 3012: 3008: 2998: 2995: 2993: 2990: 2989: 2986: 2982: 2976: 2972: 2962: 2959: 2957: 2954: 2952: 2949: 2948: 2945: 2941: 2936: 2932: 2918: 2915: 2914: 2912: 2908: 2902: 2899: 2897: 2894: 2892: 2891:Polydivisible 2889: 2887: 2884: 2882: 2879: 2877: 2874: 2872: 2869: 2868: 2866: 2862: 2856: 2853: 2851: 2848: 2846: 2843: 2841: 2838: 2836: 2833: 2832: 2830: 2827: 2822: 2816: 2813: 2811: 2808: 2806: 2803: 2801: 2798: 2796: 2793: 2791: 2788: 2786: 2783: 2782: 2780: 2777: 2773: 2765: 2762: 2761: 2760: 2757: 2756: 2754: 2751: 2747: 2735: 2732: 2731: 2730: 2727: 2725: 2722: 2720: 2717: 2715: 2712: 2710: 2707: 2705: 2702: 2700: 2697: 2695: 2692: 2690: 2687: 2686: 2684: 2680: 2674: 2671: 2670: 2668: 2664: 2658: 2655: 2653: 2650: 2649: 2647: 2645:Digit product 2643: 2637: 2634: 2632: 2629: 2627: 2624: 2622: 2619: 2618: 2616: 2614: 2610: 2602: 2599: 2597: 2594: 2593: 2592: 2589: 2588: 2586: 2584: 2579: 2575: 2571: 2566: 2561: 2557: 2547: 2544: 2542: 2539: 2537: 2534: 2532: 2529: 2527: 2524: 2522: 2519: 2517: 2514: 2512: 2509: 2507: 2504: 2502: 2499: 2497: 2494: 2492: 2489: 2487: 2484: 2482: 2481:ErdĹ‘s–Nicolas 2479: 2477: 2474: 2472: 2469: 2468: 2465: 2460: 2456: 2450: 2446: 2432: 2429: 2427: 2424: 2423: 2421: 2419: 2415: 2409: 2406: 2404: 2401: 2399: 2396: 2394: 2391: 2390: 2388: 2386: 2382: 2376: 2373: 2371: 2368: 2366: 2363: 2361: 2358: 2356: 2353: 2351: 2348: 2347: 2345: 2343: 2339: 2333: 2330: 2328: 2325: 2324: 2322: 2320: 2316: 2310: 2307: 2305: 2302: 2300: 2299:Superabundant 2297: 2295: 2292: 2290: 2287: 2285: 2282: 2280: 2277: 2275: 2272: 2270: 2267: 2265: 2262: 2260: 2257: 2255: 2252: 2250: 2247: 2245: 2242: 2240: 2237: 2235: 2232: 2230: 2227: 2225: 2222: 2220: 2217: 2215: 2212: 2210: 2207: 2205: 2202: 2201: 2199: 2197: 2193: 2189: 2185: 2181: 2176: 2172: 2162: 2159: 2157: 2154: 2152: 2149: 2147: 2144: 2142: 2139: 2137: 2134: 2132: 2129: 2127: 2124: 2122: 2119: 2117: 2114: 2112: 2109: 2107: 2104: 2103: 2100: 2096: 2091: 2087: 2077: 2074: 2072: 2069: 2067: 2064: 2062: 2059: 2058: 2055: 2051: 2046: 2042: 2032: 2029: 2027: 2024: 2022: 2019: 2017: 2014: 2012: 2009: 2007: 2004: 2002: 1999: 1997: 1994: 1992: 1989: 1987: 1984: 1982: 1979: 1977: 1974: 1972: 1969: 1967: 1964: 1962: 1959: 1957: 1954: 1952: 1949: 1947: 1944: 1942: 1939: 1937: 1934: 1933: 1930: 1923: 1919: 1901: 1898: 1896: 1893: 1891: 1888: 1887: 1885: 1881: 1878: 1876: 1875:4-dimensional 1872: 1862: 1859: 1858: 1856: 1854: 1850: 1844: 1841: 1839: 1836: 1834: 1831: 1829: 1826: 1824: 1821: 1819: 1816: 1815: 1813: 1811: 1807: 1801: 1798: 1796: 1793: 1791: 1788: 1786: 1785:Centered cube 1783: 1781: 1778: 1777: 1775: 1773: 1769: 1766: 1764: 1763:3-dimensional 1760: 1750: 1747: 1745: 1742: 1740: 1737: 1735: 1732: 1730: 1727: 1725: 1722: 1720: 1717: 1715: 1712: 1710: 1707: 1705: 1702: 1701: 1699: 1697: 1693: 1687: 1684: 1682: 1679: 1677: 1674: 1672: 1669: 1667: 1664: 1662: 1659: 1657: 1654: 1652: 1649: 1647: 1644: 1643: 1641: 1639: 1635: 1632: 1630: 1629:2-dimensional 1626: 1622: 1618: 1613: 1609: 1599: 1596: 1594: 1591: 1589: 1586: 1584: 1581: 1579: 1576: 1574: 1573:Nonhypotenuse 1571: 1570: 1567: 1560: 1556: 1546: 1543: 1541: 1538: 1536: 1533: 1531: 1528: 1526: 1523: 1522: 1519: 1512: 1508: 1498: 1495: 1493: 1490: 1488: 1485: 1483: 1480: 1478: 1475: 1473: 1470: 1468: 1465: 1463: 1460: 1459: 1456: 1451: 1446: 1442: 1432: 1429: 1427: 1424: 1422: 1419: 1417: 1414: 1412: 1409: 1408: 1405: 1398: 1394: 1384: 1381: 1379: 1376: 1374: 1371: 1369: 1366: 1364: 1361: 1359: 1356: 1354: 1351: 1350: 1347: 1342: 1336: 1332: 1322: 1319: 1317: 1314: 1312: 1311:Perfect power 1309: 1307: 1304: 1302: 1301:Seventh power 1299: 1297: 1294: 1292: 1289: 1287: 1284: 1282: 1279: 1277: 1274: 1272: 1269: 1267: 1264: 1262: 1259: 1257: 1254: 1253: 1250: 1245: 1240: 1236: 1232: 1224: 1219: 1217: 1212: 1210: 1205: 1204: 1201: 1187:on 2017-10-14 1186: 1182: 1178: 1174: 1169: 1167: 1166: 1161: 1160: 1156: 1147: 1140: 1137: 1132: 1130:0-471-19334-8 1126: 1122: 1115: 1112: 1109: 1104: 1101: 1096: 1089: 1086: 1080: 1079: 1074: 1071: 1064: 1061: 1054: 1050: 1047: 1046: 1042: 1040: 1037: 1029: 1024: 1023: 1022: 1016: 1015: 1014: 1008: 1007: 1006: 1000: 999: 998: 992: 990: 984: 983: 982: 976: 971: 966: 965: 964: 958: 955: 952: 949: 946: 943: 940: 937: 934: 931: 930: 929: 926: 922: 914: 911: 910: 906: 903: 902: 898: 895: 894: 890: 887: 886: 882: 879: 878: 874: 871: 870: 866: 863: 862: 859: 855: 853: 850: 849: 841: 839: 837: 833: 829: 824: 810: 802: 786: 766: 746: 726: 723: 715: 693: 689: 681: 677: 672: 669: 666: 660: 657: 654: 650: 642: 638: 630: 626: 618: 614: 609: 606: 603: 597: 594: 591: 587: 579: 575: 551: 531: 523: 522:concatenation 507: 504: 482: 478: 455: 451: 430: 427: 424: 421: 418: 392: 388: 383: 380: 377: 371: 368: 365: 361: 353: 349: 344: 341: 334: 317: 313: 308: 305: 302: 296: 293: 290: 286: 278: 274: 269: 266: 259: 258: 257: 243: 223: 203: 183: 157: 153: 148: 145: 142: 136: 133: 130: 127: 123: 115: 112: 108: 103: 100: 93: 92: 91: 77: 74: 54: 42: 40: 38: 34: 31: 27: 23: 19: 2900: 2855:Transposable 2719:Narcissistic 2626:Digital root 2546:Super-Poulet 2506:Jordan–PĂłlya 2455:prime factor 2360:Noncototient 2327:Almost prime 2309:Superperfect 2284:Refactorable 2279:Quasiperfect 2254:Hyperperfect 2095:Pseudoprimes 2066:Wall–Sun–Sun 2001:Ordered Bell 1971:Fuss–Catalan 1883:non-centered 1833:Dodecahedral 1810:non-centered 1696:non-centered 1598:Wolstenholme 1343:× 2 ± 1 1340: 1339:Of the form 1306:Eighth power 1286:Fourth power 1189:. Retrieved 1185:the original 1176: 1164: 1139: 1120: 1114: 1103: 1088: 1076: 1063: 1033: 1020: 1012: 1004: 996: 988: 980: 962: 927: 923: 920: 915:11039126154 857: 851: 835: 825: 800: 410: 236:, each with 175: 46: 25: 21: 15: 2876:Extravagant 2871:Equidigital 2826:permutation 2785:Palindromic 2759:Automorphic 2657:Sum-product 2636:Sum-product 2591:Persistence 2486:ErdĹ‘s–Woods 2408:Untouchable 2289:Semiperfect 2239:Hemiperfect 1900:Tesseractic 1838:Icosahedral 1818:Tetrahedral 1749:Dodecagonal 1450:Recursively 1321:Prime power 1296:Sixth power 1291:Fifth power 1271:Power of 10 1229:Classes of 1181:Brady Haran 1177:Numberphile 1030:Other bases 714:permutation 3088:Graphemics 2961:Pernicious 2815:Undulating 2790:Pandigital 2764:Trimorphic 2365:Nontotient 2214:Arithmetic 1828:Octahedral 1729:Heptagonal 1719:Pentagonal 1704:Triangular 1545:SierpiĹ„ski 1467:Jacobsthal 1266:Power of 3 1261:Power of 2 1191:2013-04-08 1055:References 907:208423682 739:digits of 411:such that 43:Definition 2845:Parasitic 2694:Factorion 2621:Digit sum 2613:Digit sum 2431:Fortunate 2418:Primorial 2332:Semiprime 2269:Practical 2234:Descartes 2229:Deficient 2219:Betrothed 2061:Wieferich 1890:Pentatope 1853:pyramidal 1744:Decagonal 1739:Nonagonal 1734:Octagonal 1724:Hexagonal 1583:Practical 1530:Congruent 1462:Fibonacci 1426:Loeschian 1123:. Wiley. 1078:MathWorld 658:− 595:− 422:× 369:− 294:− 134:− 30:composite 3137:Category 2917:Friedman 2850:Primeval 2795:Repdigit 2752:-related 2699:Kaprekar 2673:Meertens 2596:Additive 2583:dynamics 2491:Friendly 2403:Sociable 2393:Amicable 2204:Abundant 2184:dynamics 2006:Schröder 1996:Narayana 1966:Eulerian 1956:Delannoy 1951:Dedekind 1772:centered 1638:centered 1525:Amenable 1482:Narayana 1472:Leonardo 1368:Mersenne 1316:Powerful 1256:Achilles 1043:See also 899:4390670 842:Examples 256:digits: 90:digits: 3090:related 3054:related 3018:related 3016:Sorting 2901:Vampire 2886:Harshad 2828:related 2800:Repunit 2714:Lychrel 2689:Dudeney 2541:Størmer 2536:Sphenic 2521:Regular 2459:divisor 2398:Perfect 2294:Sublime 2264:Perfect 1991:Motzkin 1946:Catalan 1487:Padovan 1421:Leyland 1416:Idoneal 1411:Hilbert 1383:Woodall 1036:base 12 973:in the 970:A014575 891:108454 830:to the 716:of the 28:) is a 2956:Odious 2881:Frugal 2835:Cyclic 2824:Digit- 2531:Smooth 2516:Pronic 2476:Cyclic 2453:Other 2426:Euclid 2076:Wilson 2050:Primes 1709:Square 1578:Polite 1540:Riesel 1535:Knödel 1497:Perrin 1378:Thabit 1363:Fermat 1353:Cullen 1276:Square 1244:Powers 1127:  1039:once. 832:Usenet 712:are a 37:digits 2997:Prime 2992:Lucky 2981:sieve 2910:Other 2896:Smith 2776:Digit 2734:Happy 2709:Keith 2682:Other 2526:Rough 2496:Giuga 1961:Euler 1823:Cubic 1477:Lucas 1373:Proth 883:3228 801:fangs 176:Then 2951:Evil 2631:Self 2581:and 2471:Blum 2182:and 1986:Lobb 1941:Cake 1936:Bell 1686:Star 1593:Ulam 1492:Pell 1281:Cube 1125:ISBN 975:OEIS 875:148 779:and 544:and 470:and 216:and 47:Let 24:(or 20:, a 3069:Ban 2457:or 1976:Lah 803:of 524:of 16:In 3139:: 1179:. 1175:. 1075:. 912:16 904:14 896:12 888:10 867:7 838:. 823:. 443:, 1341:a 1222:e 1215:t 1208:v 1194:. 1148:. 1133:. 1097:. 1081:. 977:) 880:8 872:6 864:4 858:n 852:n 811:N 787:B 767:A 747:N 727:k 724:2 700:) 694:1 690:b 682:2 678:b 673:. 670:. 667:. 661:1 655:k 651:b 643:k 639:b 631:1 627:a 619:2 615:a 610:. 607:. 604:. 598:1 592:k 588:a 580:k 576:a 571:( 552:B 532:A 508:k 505:2 483:1 479:b 456:1 452:a 431:N 428:= 425:B 419:A 393:1 389:b 384:. 381:. 378:. 372:1 366:k 362:b 354:k 350:b 345:= 342:B 318:1 314:a 309:. 306:. 303:. 297:1 291:k 287:a 279:k 275:a 270:= 267:A 244:k 224:B 204:A 184:N 158:1 154:n 149:. 146:. 143:. 137:1 131:k 128:2 124:n 116:k 113:2 109:n 104:= 101:N 78:k 75:2 55:N

Index

recreational mathematics
composite
natural number
digits
concatenation
permutation
Clifford A. Pickover
Usenet
A014575
OEIS
base 12
Friedman number
Weisstein, Eric W.
"Vampire Numbers"
MathWorld
"Vampire numbers"
Pickover's original post describing vampire numbers
ISBN
0-471-19334-8
"Vampire Numbers Visualized"
Vampire Numbers Visualized
"Vampire numbers"
Brady Haran
the original
v
t
e
natural numbers
Powers
Achilles

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