Enter a number to check if it's a lucky number, or input a range to generate all lucky numbers within it.
A lucky number is a sequence of integers derived through a unique filtering process. This process is mathematically akin to a sieve, similar to the sieve method for finding prime numbers. Lucky numbers were first described by the 19th-century mathematician Joseph Bertrand.
The Filtering Process:
1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79, 87, 93, 99, 105, 111, 115, 127, 129, 133, 135, 141, 151, 159, 163, 169, 171, 189, 193, 195, 201, 205, 211, 219, 223, 231, 235, 237, 241, 259, 261, 267, 273, 283, 285, 289, 297, 303, 307, 319, 321, 327, 331, 339, 349, 357, 361, 367, 385, 391, 393, 399, 409, 415, 421, 427, 429, 433, 451, 463, 475, 477, 483, 487, 489, 495, 511, 517, 519, 529, 535, 537, 541, 553, 559, 577, 579, 583, 591, 601, 613, 615, 619, 621, 631, 639, 643, 645, 651, 655, 673, 679, 685, 693, 699, 717, 723, 727, 729, 735, 739, 741, 745, 769, 777, 781, 787, 801, 805, 819, 823, 831, 841, 855, 867, 873, 883, 885, 895, 897, 903, 925, 927, 931, 933, 937, 957, 961, 975, 979, 981, 991, 993, 997, 1009, 1011, 1021, 1023, 1029, 1039, 1041, 1053, 1057, 1087, 1093, 1095, 1101, 1105, 1107, 1117, 1123, 1147, 1155, 1167, 1179, 1183, 1189, 1197, 1201, 1203, 1209, 1219, 1231, 1233, 1245, 1249, 1251, 1261, 1263, 1275, 1281, 1285, 1291, 1303, 1309, 1323, 1329, 1339, 1357, 1365, 1369, 1387, 1389, 1395, 1401, 1417, 1419, 1435, 1441, 1455, 1459, 1471, 1473, 1485, 1491, 1495, 1497, 1501, 1503, 1519, 1533, 1543, 1545, 1563, 1567, 1575, 1579, 1585, 1587, 1597, 1599, 1611, 1639, 1641, 1645, 1659, 1663, 1675, 1693, 1701, 1705, 1711, 1723, 1731, 1737, 1749, 1765, 1767, 1771, 1773, 1777, 1797, 1801, 1809, 1819, 1827, 1831, 1833, 1839, 1857, 1869, 1879, 1893, 1899, 1915, 1921, 1923, 1933, 1941, 1945, 1959, 1963, 1965, 1977, 1983, 1987, 1995, 2001, 2019, 2023, 2031, 2053, 2059, 2065, 2067, 2079, 2083, 2085, 2095, 2113, 2115, 2121, 2125, 2127, 2133, 2163, 2173, 2187, 2209, 2211, 2215, 2217, 2221, 2239, 2251, 2253, 2257, 2271, 2277, 2281, 2283, 2301, 2311, 2317, 2323, 2335, 2343, 2355, 2365, 2379, 2395, 2403, 2407, 2409, 2415, 2419, 2427, 2439, 2445, 2461, 2467, 2473, 2479, 2491, 2493, 2505, 2511, 2523, 2527, 2545, 2557, 2563, 2571, 2575, 2587, 2589, 2593, 2599, 2607, 2625, 2635, 2647, 2649, 2653, 2661, 2667, 2671, 2689, 2697, 2715, 2725, 2755, 2763, 2773, 2781, 2785, 2787, 2797, 2815, 2817, 2821, 2823, 2827, 2835, 2841, 2845, 2851, 2877, 2887, 2899, 2901, 2905, 2913, 2923, 2943, 2953, 2961, 2971, 2973, 2977, 2983, 3003, 3007, 3027, 3031, 3037, 3039, 3049, 3055, 3073, 3075, 3091, 3097, 3099, 3109, 3111, 3121, 3123, 3133, 3153, 3163, 3171, 3175, 3183, 3187, 3199, 3213, 3223, 3229, 3235, 3243, 3259, 3261, 3289, 3297, 3301, 3307, 3313, 3325, 3339, 3351, 3355, 3363, 3381, 3403, 3405, 3409, 3411, 3427, 3433, 3439, 3451, 3453, 3465, 3477, 3481, 3487, 3489, 3495, 3499, 3507, 3559, 3565, 3571, 3579, 3595, 3597, 3603, 3607, 3613, 3621, 3625, 3633, 3655, 3661, 3663, 3669, 3675, 3685, 3687, 3697, 3709, 3717, 3721, 3727, 3747, 3753, 3763, 3771, 3781, 3789, 3793, 3795, 3811, 3843, 3847, 3849, 3865, 3873, 3879, 3889, 3891, 3897, 3909, 3915, 3931, 3943, 3951, 3955, 3969, 3975, 3981, 3991, 3999, 4003, 4015, 4023, 4033, 4035, 4041, 4045, 4063, 4069, 4081, 4095, 4105, 4107, 4129, 4131, 4161, 4165, 4173, 4179, 4189, 4195, 4201, 4203, 4207, 4227, 4237, 4251, 4255, 4257, 4263, 4269, 4285, 4287, 4315, 4321, 4329, 4335, 4363, 4377, 4383, 4389, 4399, 4413, 4431, 4441, 4443, 4455, 4461, 4465, 4483, 4485, 4495, 4509, 4519, 4521, 4539, 4551, 4561, 4567, 4569, 4573, 4587, 4609, 4611, 4621, 4623, 4629, 4645, 4647, 4653, 4663, 4671, 4675, 4695, 4699, 4713, 4717, 4725, 4741, 4761, 4767, 4773, 4797, 4801, 4809, 4813, 4819, 4833, 4837, 4839, 4843, 4851, 4863, 4867, 4881, 4887, 4893, 4929, 4951, 4963, 4965, 4969, 4977, 4987, 4989, 4993, 4999, 5001, 5007, 5019, 5029, 5041, 5043, 5049, 5053, 5089, 5103, 5127, 5137, 5139, 5149, 5151, 5157, 5169, 5179, 5181, 5191, 5211, 5217, 5229, 5233, 5235, 5253, 5259, 5277, 5283, 5293, 5295, 5299, 5325, 5335, 5341, 5343, 5371, 5377, 5379, 5385, 5409, 5419, 5427, 5433, 5449, 5455, 5463, 5473, 5487, 5491, 5503, 5515, 5527, 5547, 5551, 5559, 5569, 5577, 5587, 5589, 5593, 5599, 5613, 5617, 5637, 5641, 5649, 5655, 5661, 5671, 5673, 5679, 5691, 5701, 5707, 5713, 5719, 5737, 5755, 5763, 5767, 5769, 5803, 5809, 5817, 5827, 5833, 5839, 5851, 5869, 5883, 5889, 5893, 5901, 5905, 5911, 5913, 5923, 5959, 5965, 5967, 5971, 5973, 5977, 5991, 5997, 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093, 6111, 6115, 6123, 6141, 6147, 6159, 6163, 6175, 6177, 6195, 6211, 6229, 6237, 6243, 6249, 6253, 6271, 6273, 6279, 6301, 6309, 6331, 6345, 6351, 6355, 6363, 6367, 6369, 6373, 6379, 6385, 6399, 6411, 6415, 6427, 6433, 6435, 6447, 6463, 6471, 6475, 6477, 6501, 6505, 6523, 6531, 6535, 6541, 6553, 6559, 6567, 6573, 6601, 6621, 6625, 6631, 6661, 6663, 6667, 6669, 6679, 6687, 6693, 6715, 6723, 6733, 6741, 6745, 6747, 6753, 6757, 6763, 6765, 6783, 6787, 6789, 6841, 6849, 6867, 6871, 6883, 6891, 6909, 6915, 6921, 6931, 6933, 6937, 6951, 6981, 6985, 6999, 7003, 7009, 7035, 7041, 7045, 7047, 7069, 7077, 7081, 7087, 7101, 7111, 7129, 7135, 7153, 7167, 7171, 7173, 7183, 7191, 7195, 7197, 7207, 7215, 7231, 7233, 7237, 7245, 7249, 7279, 7293, 7299, 7311, 7321, 7333, 7339, 7341, 7345, 7357, 7359, 7371, 7377, 7395, 7401, 7405, 7419, 7435, 7437, 7443, 7447, 7459, 7471, 7489, 7501, 7503, 7507, 7531, 7533, 7549, 7551, 7563, 7567, 7575, 7585, 7591, 7593, 7603, 7609, 7629, 7633, 7639, 7645, 7677, 7687, 7689, 7701, 7711, 7717, 7737, 7755, 7779, 7791, 7795, 7801, 7803, 7813, 7827, 7833, 7837, 7855, 7881, 7885, 7897, 7899, 7909, 7917, 7921, 7929, 7939, 7947, 7951, 7963, 7969, 7971, 8001, 8005, 8007, 8013, 8037, 8047, 8071, 8073, 8085, 8089, 8107, 8109, 8127, 8131, 8139, 8151, 8161, 8169, 8173, 8175, 8191, 8193, 8221, 8223, 8227, 8233, 8253, 8257, 8263, 8269, 8283, 8289, 8299, 8325, 8331, 8347, 8359, 8365, 8367, 8379, 8409, 8413, 8421, 8445, 8449, 8467, 8473, 8475, 8479, 8487, 8493, 8515, 8535, 8539, 8551, 8553, 8575, 8577, 8583, 8589, 8601, 8605, 8611, 8617, 8635, 8637, 8641, 8647, 8655, 8661, 8673, 8683, 8719, 8757, 8769, 8773, 8787, 8793, 8805, 8809