This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A130326 #7 Sep 01 2013 11:37:10
%S A130326 2,2,3,3,2,2,3,2,19,5,5,2,5,11,3,47,7,2,11,19,47,11,11,59,97,11,23,5,
%T A130326 11,2,31,13,37,3,53,2,71,5,5,97,2,7,3,3,5,167,41,37,5,163,23,73,31,17,
%U A130326 59,19,29,41,73,43,59,47,71,3,109,2,11,3,79,41,13
%N A130326 Least prime p such that 3*p*2^n+1 is prime.
%H A130326 Pierre CAMI, <a href="/A130326/b130326.txt">Table of n, a(n) for n = 0..500</a>
%e A130326 3*2*2^0+1=7 prime so for n=0 p=2
%e A130326 3*2*2^1+1=13 prime so for n=1 p=2
%t A130326 nn=100;Flatten[Module[{prs=Prime[Range[nn]],c},Table[c=2^n;Select[prs, PrimeQ[ 3c #+1]&,1],{n,0,nn}]]] (* _Harvey P. Dale_, Sep 01 2013 *)
%Y A130326 Cf. A130325, A130327.
%K A130326 nonn
%O A130326 0,1
%A A130326 _Pierre CAMI_, May 24 2007
%E A130326 More terms from _Harvey P. Dale_, Sep 01 2013