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 A186300 #8 Mar 31 2012 10:25:40 %S A186300 3,7,15,19,27,31,51,55,75,79,87,91,99,115,135,139,147,159,175,187,195, %T A186300 199,211,231,255,271,279,307,327,331,339,351,355,367,379,387,399,411, %U A186300 415,427,439,471,499,507,511,531,535,547,555,559,591,607 %N A186300 (A007521(n)+1)/2. %F A186300 a(n) = A186299(n)+1. %K A186300 nonn %O A186300 1,1 %A A186300 _Marco Matosic_, Feb 17 2011