A292896
Numbers m such that there are precisely 13 groups of order m.
Original entry on oeis.org
56, 60, 150, 189, 441, 726, 837, 945, 1012, 1161, 1204, 1521, 1575, 1647, 1734, 1809, 1988, 2079, 2133, 2205, 2366, 2619, 2781, 2925, 2948, 3174, 3213, 3556, 3610, 3753, 4077, 4239, 4324, 4347, 4851, 5046, 5211, 5697, 5805, 5908, 6021, 6183, 6507, 6692, 7479, 7497, 7605, 7623, 7641, 7749, 8410, 8451
Offset: 1
The 13 groups of order 56 have the following structure C7 : C8, C56, C7 : Q8, C4 x D14, D56, C2 x (C7 : C4), (C14 x C2) : C2, C28 x C2, C7 x D8, C7 x Q8, (C2 x C2 x C2) : C7, C2 x C2 x D14, C14 x C2 x C2 where C, D and Q mean Cyclic group, Dihedral group and Quarternion group of the stated order. The symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12), this sequence (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
A249550
Numbers m such that there are precisely 7 groups of order m.
Original entry on oeis.org
375, 605, 903, 1705, 2255, 2601, 2667, 3081, 3355, 3905, 3993, 4235, 4431, 4515, 4805, 5555, 6123, 6355, 6375, 6765, 7077, 7205, 7865, 7917, 7959, 8305, 8405, 8625, 8841, 9455, 9723, 9933, 9955, 10285, 10505, 10875, 11005, 11487, 11495, 11571, 11605, 11715, 11935, 12207, 12505, 13005, 13053, 13251, 13255, 13335, 13805, 14133
Offset: 1
For m = 375, the 7 groups are C375, ((C5 x C5) : C5) : C3, C75 x C5, C3 x ((C5 x C5) : C5), C3 x (C25 : C5), C5 x ((C5 x C5) : C3), C15 x C5 x C5 and for n = 605 the 7 groups are C121 : C5, C605, C11 x (C11 : C5), (C11 x C11) : C5, (C11 x C11) : C5, (C11 x C11) : C5, C55 x C11, where C means Cyclic group and the symbols x and : mean direct and semidirect products respectively. - _Muniru A Asiru_, Nov 11 2017
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6), this sequence (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
-
Warning: The Mma command Select[Range[10^5], FiniteGroupCount[#]==7 &] gives wrong answers, since FiniteGroupCount[2601] does not return 7. - N. J. A. Sloane, Apr 11 2020
A294155
Numbers m such that there are precisely 14 groups of order m.
Original entry on oeis.org
16, 36, 40, 104, 232, 296, 351, 424, 488, 808, 872, 1125, 1192, 1197, 1256, 1384, 1448, 1576, 1755, 1832, 2152, 2216, 2223, 2331, 2344, 2536, 2625, 2792, 2984, 3112, 3176, 3368, 3688, 3861, 4072, 4328, 4329, 4456, 4599, 4875, 4904, 5115, 5187, 5224, 5288, 5301
Offset: 1
For m = 16, the 14 groups of order 16 are C16, C4 x C4, (C4 x C2) : C2, C4 : C4, C8 x C2, C8 : C2, D16, QD16, Q16, C4 x C2 x C2, C2 x D8, C2 x Q8, (C4 x C2) : C2, C2 x C2 x C2 x C2 and for n = 36 the 14 groups of order 36 are C9 : C4, C36, (C2 x C2) : C9, D36, C18 x C2, C3 x (C3 : C4), (C3 x C3) : C4, C12 x C3, (C3 x C3) : C4, S3 x S3, C3 x A4, C6 x S3, C2 x ((C3 x C3) : C2), C6 x C6 where C, D, Q mean Cyclic group, Dihedral group, Quaternion group of the stated order and S is the Symmetric group of the stated degree. The symbols x and : mean direct and semi-direct products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13), this sequence (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
A294156
Numbers m such that there are precisely 15 groups of order m.
Original entry on oeis.org
24, 54, 81, 84, 136, 220, 228, 250, 260, 328, 340, 372, 513, 516, 580, 584, 620, 625, 686, 712, 740, 776, 804, 884, 891, 904, 948, 999, 1060, 1096, 1236, 1375, 1377, 1420, 1460, 1508, 1524, 1544, 1668, 1780, 1812, 1863, 1864, 1911, 1924, 1928, 1940, 1956, 1971, 1972, 2056, 2132, 2180
Offset: 1
For m = 24, the 15 groups of order 24 are C3 : C8, C24, SL(2,3), C3 : Q8, C4 x S3, D24, C2 x (C3 : C4), (C6 x C2) : C2, C12 x C2, C3 x D8, C3 x Q8, S4, C2 x A4, C2 x C2 x S3, C6 x C2 x C2 and for n = 54 the 15 groups of order 54 are D54, C54, C3 x D18, C9 x S3, ((C3 x C3) : C3) : C2, (C9 : C3) : C2, (C9 x C3) : C2, ((C3 x C3) : C3) : C2, C18 x C3, C2 x ((C3 x C3) : C3), C2 x (C9 : C3), C3 x C3 x S3, C3 x ((C3 x C3) : C2), (C3 x C3 x C3) : C2, C6 x C3 x C3 where C, D, Q, S, A and SL mean Cyclic, Dihedral, Quaternion, Symmetric, Alternating and Special Linear group. The symbols x and : mean direct and semi-direct products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14), this sequence (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
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A294156 := Filtered([1..2015], n -> NumberSmallGroups(n) = 15);
-
Select[ Range@2000, FiniteGroupCount@# == 15 &] (* Robert G. Wilson v, Oct 24 2017 *)
A295161
Numbers m such that there are precisely 16 groups of order m.
Original entry on oeis.org
100, 126, 234, 405, 550, 558, 676, 774, 812, 1098, 1156, 1206, 1218, 1422, 1550, 1746, 1854, 2050, 2502, 2530, 2718, 2826, 2842, 2943, 2982, 3050, 3164, 3364, 3474, 3550, 3798, 3875, 3916, 4014, 4122, 4134, 4214, 4275, 4338, 4401, 4746, 4986, 5094, 5476, 5516, 5566, 5634, 5958, 6066, 6282
Offset: 1
For m = 100, the 16 groups are C25 : C4, C100, C25 : C4, D100, C50 x C2, C5 x (C5 : C4), (C5 x C5) : C4, C20 x C5, C5 x (C5 : C4), (C5 x C5) : C4, (C5 x C5) : C4, (C5 x C5) : C4, D10 x D10, C10 x D10, C2 x ((C5 x C5) : C2), C10 x C10 where C, D mean Cyclic, Dihedral groups of the stated order and the symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15), this sequence (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
A294949
Numbers m such that there are precisely 17 groups of order m.
Original entry on oeis.org
675, 3267, 3549, 9947, 11475, 12625, 14283, 14749, 15525, 17745, 18875, 19575, 22707, 24353, 31725, 35775, 38759, 39039, 39825, 41209, 43561, 45387, 49735
Offset: 1
For m = 675, the 17 groups are C675, C225 x C3, C25 x ((C3 x C3) : C3), C25 x (C9 : C3), (C5 x C5) : C27, C135 x C5, C75 x C3 x C3, C9 x ((C5 x C5) : C3), (C45 x C5) : C3, C3 x ((C5 x C5) : C9), ((C5 x C5) : C9) : C3, (C15 x C15) : C3, C45 x C15, C5 x C5 x ((C3 x C3) : C3), C5 x C5 x (C9 : C3), C3 x C3 x ((C5 x C5) : C3), C15 x C15 x C3 where C means Cyclic group and the symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16), this sequence (k=17),
A298909 (k=18),
A298910 (k=19),
A298911 (k=20).
A298909
Numbers m such that there are precisely 18 groups of order m.
Original entry on oeis.org
156, 342, 444, 666, 732, 876, 930, 1164, 1308, 1314, 1830, 1884, 1962, 2172, 2286, 2316, 2748, 2892, 2934, 3258, 3324, 3582, 3675, 3756, 4044, 4125, 4188, 4422, 4476, 4530, 4764, 4878, 4908, 4970, 5050, 5052, 5196, 5430, 5445, 5481, 5484, 5526, 6330, 6492, 6822, 6924
Offset: 1
For m = 156, the 18 groups are (C13 : C4) : C3, C4 x (C13 : C3), C13 x (C3 : C4), C3 x (C13 : C4), C39 : C4, C156, (C13 : C4) : C3, C2 x ((C13 : C3) : C2), C3 x (C13 : C4), C39 : C4, S3 x D26, C2 x C2 x (C13 : C3), C13 x A4, (C26 x C2) : C3, C6 x D26, C26 x S3, D156, C78 x C2 where C, D mean Cyclic, Dihedral groups of the stated order and S, A mean the Symmetric, Alternating groups of the stated degree. The symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17), this sequence (k=18),
A298910 (k=19),
A298911 (k=20).
-
Filtered([1..2015], n -> NumberSmallGroups(n) = 18);
-
with(GroupTheory):
for n from 1 to 10^4 do if NumGroups(n) = 18 then print(n); fi; od;
A298911
Numbers m such that there are precisely 20 groups of order m.
Original entry on oeis.org
820, 1220, 1530, 2020, 2070, 2610, 2756, 3366, 3620, 4230, 4550, 4770, 4820, 5310, 5620, 5742, 5950, 6370, 6650, 7038, 7470, 8010, 8020, 8050, 8118, 8164, 8330, 8420, 8874, 9220, 9306, 9310, 9316, 9630, 10170, 10420, 10494, 10820, 11050
Offset: 1
For m = 820, the 20 groups are (C41 : C5) : C4, C4 x (C41 : C5), C41 x (C5 : C4), C5 x (C41 : C4), C205 : C4, C820, (C41 : C5) : C4, C2 x ((C41 : C5) : C2), C2 x C2 x (C41 : C5), C5 x (C41 : C4), C41 x (C5 : C4), C205 : C4, C205 : C4, C205 : C4, C205 : C4, D10 x D82, C10 x D82, C82 x D10, D820, C410 x C2 where C, D mean the Cyclic, Dihedral groups of the stated order and the symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18),
A298910 (k=19), this sequence (k=20).
A298910
Numbers m such that there are precisely 19 groups of order m.
Original entry on oeis.org
1029, 5145, 6591, 7803, 8001, 11319, 11739, 12789, 17157, 17493, 20577, 21567, 23667, 23877, 27993, 31311, 32955, 33411, 34671, 34713, 39015, 39753, 40005, 42189, 42861, 45675, 47691, 48363, 49833
Offset: 1
For m = 1029, the 19 groups are C1029, C147 x C7, C3 x ((C7 x C7) : C7), C3 x (C49 : C7), C21 x C7 x C7, C343 : C3, C49 x (C7 : C3), C7 x (C49 : C3), (C49 x C7) : C3, (C49 x C7) : C3, ((C7 x C7) : C7) : C3, ((C7 x C7) : C7) : C3, ((C7 x C7) : C7) : C3, (C49 : C7) : C3, C7 x ((C7 x C7) : C3), C7 x ((C7 x C7) : C3), (C7 x C7 x C7) : C3, (C7 x C7 x C7) : C3, C7 x C7 x (C7 : C3) where C means the Cyclic group of the stated order and the symbols x and : mean direct and semidirect products respectively.
Cf.
A000001. Cyclic numbers
A003277. Numbers m such that there are precisely k groups of order m:
A054395 (k=2),
A055561 (k=3),
A054396 (k=4),
A054397 (k=5),
A135850 (k=6),
A249550 (k=7),
A249551 (k=8),
A249552 (k=9),
A249553 (k=10),
A249554 (k=11),
A249555 (k=12),
A292896 (k=13),
A294155 (k=14),
A294156 (k=15),
A295161 (k=16),
A294949 (k=17),
A298909 (k=18), this sequence (k=19),
A298911 (k=20).
Shortened to remove possibly incorrect terms by
Andrew Howroyd, Jan 28 2022
A298429
Numbers n such that there are precisely 12 groups of orders n and n + 1.
Original entry on oeis.org
30135, 76312, 130890, 173445, 356610
Offset: 1
For n = 30135, A000001(30135) = A000001(30136) = 12.
For n = 76312, A000001(76312) = A000001(76313) = 12.
For n = 130890, A000001(130890) = A000001(130891) = 12.
Cf.
A000001. Subsequence of
A249555 (Numbers n having precisely 12 groups of order n). Numbers n having precisely k groups of orders n and n+1:
A295230 (k=2),
A295990 (k=4),
A295991 (k=5),
A295992 (k=6),
A295993 (k=8),
A298427 (k=9),
A298428 (k=10),
A295994 (k=11), this sequence (k=12),
A298430 (k=13),
A298431 (k=14),
A295995 (k=15).
Comments