%I #19 Nov 02 2012 13:21:51
%S 28,40,44,63,76,88,92,104,105,112,117,124,152,165,172,176,184,188,189,
%T 195,208,224,225,231,232,236,248,268,275,279,284,285,296,304,315,316,
%U 332,344,352,357,368,375,376,385,387,412,416,424,428,429,464,472,483
%N Numbers which are not nilpotent numbers, but every group of that order has nontrivial center.
%C 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.
%H Mikko Korhonen, <a href="/A216594/b216594.txt">Table of n, a(n) for n = 1..200</a>
%e Every group of order 28 has nontrivial center, but the dihedral group of order 28 is not nilpotent.
%Y Subsequence of A056868.
%K nonn
%O 1,1
%A _Mikko Korhonen_, Sep 09 2012
