%I #5 Mar 31 2012 14:45:10
%S 7,19,37,61,127,169,271,331,397,547,631,919,1657,1801,1951,2269,2437,
%T 2791,3169,3571,4219,4447,5167,5419,6211,7057,7351,8269,9241,10267,
%U 11719,12097,13267,13669,16651,19441,19927,22447,23497,24571,25117,26227,27361
%N Hex (or centered hexagonal) numbers that are prime powers of the form (6n+1)^k.
%C Intersection of A003215 and A133290.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HexNumber.html">Hex Number</a>.
%Y Cf. A004611.
%K nonn
%O 1,1
%A _Mats Granvik_, Oct 18 2007, Oct 19 2007