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 A173872 #12 Aug 21 2014 00:41:21 %S A173872 13,37,181,373,757,3061,6133,12277,196597,1572853,25165813,805306357, %T A173872 3221225461,6442450933,12884901877,26388279066613,3377699720527861, %U A173872 1813388729421943762059253 %N A173872 Primes of the form 12*2^n - 11. %H A173872 Vincenzo Librandi, <a href="/A173872/b173872.txt">Table of n, a(n) for n = 1..33</a> %p A173872 select(isprime,[seq(12*2^n-11,n=1..1000)]); # _Robert Israel_, Aug 20 2014 %t A173872 Select[NestList[2#+11&,13,80],PrimeQ] (* _Harvey P. Dale_, Jun 18 2013 *) %Y A173872 Cf. A139697 %K A173872 nonn %O A173872 1,1 %A A173872 _Vincenzo Librandi_, Mar 05 2010