%I A127957
%S A127957 10,12,13,15,16,17,19,20,21,23,24,25,27,28,29,30,32,33,34,35,36,37,38,
%T A127957 40,41,42,44,45,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,
%U A127957 66,67,68,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89
%N A127957 Numbers n such that (2^prime(n)+1)/3 is composite.
%t A127957 a = {}; Do[c = (2^Prime[x] + 1)/3; If[PrimeQ[c] == False, AppendTo[a, 
               x]], {x, 2, 300}]; a
%Y A127957 Cf. A000979, A000978, A124400, A126614, A127955, A127956.
%Y A127957 Sequence in context: A083476 A124404 A031288 this_sequence A079026 A124867 
               A161598
%Y A127957 Adjacent sequences: A127954 A127955 A127956 this_sequence A127958 A127959 
               A127960
%K A127957 nonn
%O A127957 1,1
%A A127957 Artur Jasinski (grafix(AT)csl.pl), Feb 09 2007