%I A023204
%S A023204 2,5,7,13,17,19,29,43,47,53,67,73,89,97,113,127,137,139,157,167,173,193,
%T A023204 197,199,223,227,229,269,277,283,307,337,349,353,379,383,397,409,439,463,
%U A023204 467,487,503,509,523,547,557,563,599,607,613,617,643,647,659,739,743,773
%N A023204 Numbers n such that n and 2n + 3 both prime.
%t A023204 f[n_]:=PrimeQ[2*n+3]; lst={};Do[p=Prime[n];If[f[p],AppendTo[lst,p]],{n,
               6!}];lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 03 
               2009]
%Y A023204 Cf. A089530, A089531, A089532.
%Y A023204 Sequence in context: A161889 A069346 A023240 this_sequence A045352 A107426 
               A144256
%Y A023204 Adjacent sequences: A023201 A023202 A023203 this_sequence A023205 A023206 
               A023207
%K A023204 nonn
%O A023204 1,1
%A A023204 David W. Wilson (davidwwilson(AT)comcast.net)