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 A180269 #7 May 11 2013 11:16:05
%S A180269 2,7,37,36472996377170786527,2954312706550833698779,
%T A180269 3990838394187339929534246675572349035477,
%U A180269 2120895147045314119491609587512844743630072393,228532044137599177017869183161846685251274404207185590172004697234871412029099114059347
%N A180269 Primes of the form 3^n+3*n+1.
%C A180269 Terms a(9) through a(12) have, respectively, 93, 94, 149, and 156 digits. - _Harvey P. Dale_, May 11 2013
%H A180269 Harvey P. Dale, <a href="/A180269/b180269.txt">Table of n, a(n) for n = 1..15</a>
%t A180269 Select[Table[3^n+3n+1,{n,0,100}],PrimeQ] (* _Harvey P. Dale_, May 11 2013 *)
%o A180269 (PARI) for(i=0,200,x=3^i+3*i+1;if(isprime(x),print1(x", ")))
%Y A180269 Cf. A176805, A171058.
%K A180269 hard,nonn
%O A180269 1,1
%A A180269 Graziano Aglietti (mg5055(AT)mclink.it), Aug 23 2010
%E A180269 a(8) from _Harvey P. Dale_, May 11 2013