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 A163909 #2 Mar 31 2012 13:21:19 %S A163909 0,2,10,54,295,1613,8812 %N A163909 a(n) = A163914(2n). %Y A163909 See also A163919. %K A163909 nonn %O A163909 0,2 %A A163909 _Antti Karttunen_, Sep 19 2009