A216594 - OEIS

A216594

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

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

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OFFSET

1,1

COMMENTS

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.

LINKS

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

EXAMPLE

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

CROSSREFS

Subsequence of A056868.

Sequence in context: A034964 A195897 A109798 * A324858 A084807 A367975

Adjacent sequences: A216591 A216592 A216593 * A216595 A216596 A216597

KEYWORD

nonn

AUTHOR

Mikko Korhonen, Sep 09 2012

STATUS

approved