A056868 -id:A056868 - cp's OEIS frontend

A131933 a(n) = A056866(n)/4.

15, 30, 42, 45, 60, 75, 84, 90, 105, 120, 126, 135, 150, 165, 168, 180, 195, 210, 225, 240, 252, 255, 270, 273, 285, 294, 300, 315, 330, 336, 345, 360, 375, 378, 390, 405, 420, 435, 450, 462, 465, 480, 495, 504, 510, 525, 540, 546, 555, 570, 585, 588, 600, 612

Offset: 1

Artur Jasinski, Jul 30 2007

nonn

All orders of nonsolvable groups A056866 are divisible by 4.

Amiram Eldar, Table of n, a(n) for n = 1..10000

Cf. A001034, A060793, A056866, A056868, A131932.

A216594 Numbers which are not nilpotent numbers, but every group of that order has nontrivial center.

Original entry on oeis.org

28, 40, 44, 63, 76, 88, 92, 104, 105, 112, 117, 124, 152, 165, 172, 176, 184, 188, 189, 195, 208, 224, 225, 231, 232, 236, 248, 268, 275, 279, 284, 285, 296, 304, 315, 316, 332, 344, 352, 357, 368, 375, 376, 385, 387, 412, 416, 424, 428, 429, 464, 472, 483

Offset: 1

Mikko Korhonen, Sep 09 2012

nonn

If p > 3 is a prime and p == 3 (mod 4), then 4p is in this sequence. Since there exist infinitely many primes of the form 4k + 3, this sequence is infinite.

			Every group of order 28 has nontrivial center, but the dihedral group of order 28 is not nilpotent.

Mikko Korhonen, Table of n, a(n) for n = 1..200

Subsequence of A056868.

A300737 Numbers of the form (ki + 1)(k*j - 1) with i, j >= 1 and k >= 2.

Original entry on oeis.org

3, 5, 7, 8, 9, 11, 13, 14, 15, 17, 19, 20, 21, 23, 24, 25, 26, 27, 29, 31, 32, 33, 35, 37, 38, 39, 41, 43, 44, 45, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 59, 61, 62, 63, 64, 65, 67, 68, 69, 71, 73, 74, 75, 77, 79, 80, 81, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 95, 97, 98, 99, 101

Offset: 1

Gionata Neri, Mar 11 2018

nonn

Cf. A056868.

limit=100; v=vector(limit); for(n=0,limit, for(k=2,floor(limit^(1/2)), for(i=1,limit/k, for(j=1,limit/k,if(n==(k*i+1)*(k*j-1),v[n]=1,))))); for(n=1,limit,if(v[n],print1(n", ")))

cp's OEIS Frontend

A131933 a(n) = A056866(n)/4.

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A216594 Numbers which are not nilpotent numbers, but every group of that order has nontrivial center.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

A300737 Numbers of the form (ki + 1)(k*j - 1) with i, j >= 1 and k >= 2.

Views

Author

Keywords

Crossrefs

Programs

PARI

cp's OEIS Frontend

A131933 a(n) = A056866(n)/4.

Views

Author

Keywords

Comments

Links

Crossrefs

A216594 Numbers which are not nilpotent numbers, but every group of that order has nontrivial center.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

A300737 Numbers of the form (k*i + 1)*(k*j - 1) with i, j >= 1 and k >= 2.

Views

Author

Keywords

Crossrefs

Programs

PARI

A300737 Numbers of the form (ki + 1)(k*j - 1) with i, j >= 1 and k >= 2.