%I A121999
%S A121999 29,37,3373
%N A121999 Primes p such that p^2 divides Sierpinski number A014566[(p-1)/2].
%C A121999 A014566[n] = n^n + 1. a(n) is a subset of A003628[n] Primes congruent 
               to {5, 7} mod 8, because prime p divides A014566[(p-1)/2] iff p belong 
               to A003628[n].
%H A121999 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               SierpinskiNumberoftheFirstKind.html">Link to a section of The World 
               of Mathematics. Sierpinski Number of the First Kind</a>.
%t A121999 Do[p=Prime[n];f=((p-1)/2)^((p-1)/2)+1;If[IntegerQ[f/p^2],Print[p]],{n,
               1,3373}]
%Y A121999 Cf. A014566, A003628.
%Y A121999 Sequence in context: A167470 A152865 A108272 this_sequence A069530 A087144 
               A114616
%Y A121999 Adjacent sequences: A121996 A121997 A121998 this_sequence A122000 A122001 
               A122002
%K A121999 bref,more,nonn
%O A121999 1,1
%A A121999 Alexander Adamchuk (alex(AT)kolmogorov.com), Sep 11 2006