Search a number
pernicious n.  and  practical n.

First numbers that belong to both sets:

6, 12, 18, 20, 24, 28, 36, 40, 42, 48, 56, 66, 72, 80, 84, 88, 96, 100, 104, 112, 132, 140, 144, 160, 162, 168, 176, 192, 196, 200, 208, 220, 224, 234, 260, 264, 272, 276, 280, 288, 304, 320, 324, 336, 342, 348, 352, 364, 384, 392, 400, 416, 440, 448, 460, 468, 496, 520, 522, 528, 532, 544, 546, 552, 558, 560, 570, 576, 580, 608, 620, 640, 644, 648, 666, 672, 684, 690, 696, 702, 704, 714, 728, 740, 744, 750, 768, 784, 800, 810, 812, 820, 832, 868, 880, 896, 920, 930, 936, 968, 992, 1026, 1032, 1036, 1040, 1044, 1056, 1064, 1088, 1092, 1104, 1110, 1116, 1120, 1140, 1144, 1152, 1160, 1184, 1204, 1216, 1240, 1280, 1288, 1296, 1302, 1312, 1332, 1344, 1350, 1368, 1380, 1392, 1404, 1408, 1428, 1456, 1476, 1480, 1488, 1500, 1504, 1536, 1540, 1568, 1600, 1620, 1624, 1640, 1664, 1674, 1700, 1710, 1722, 1736, 1760, 1770, 1792, 1840, 1860, 1872, 1888, 1900, 1908, 1936, 1952, 1976, 1984, 2024, 2052, 2058, 2064, 2072, 2080, 2088, 2106, 2112, 2120, 2128, 2156, 2176, 2178, 2184, 2190, 2208, 2214, 2220, 2226, 2232, 2240, 2250, 2280, 2288, 2300, 2304, 2320, 2360, 2368, 2380, 2392, 2408, 2432, 2442, 2478, 2480, 2500, 2538, 2548, 2552, 2560, 2562, 2574, 2576, 2592, 2604, 2610, 2624, 2660, 2664, 2688, 2700, 2706, 2728, 2736, 2754, 2760, 2784, 2790, 2808, 2816, 2840, 2850, 2856, 2862, 2912, 2952, 2960, 2970, 2976, 2982, 2988, 3000, 3008, 3042, 3072, 3080, 3100, 3136, 3160, 3200, 3220, 3224, 3234, 3240, 3248, 3280, 3320, 3328, 3348, 3388, 3400, 3408, 3420, 3444, 3472, 3498, 3500, 3520, 3540, 3560, 3584, 3608, 3618, 3630, 3680, 3690, 3700, 3720, 3726, 3738.

Some larger examples :