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 A163919 #2 Mar 31 2012 13:21:19 %S A163919 0,1,9,57,329,1834,10072 %N A163919 a(n) = A163914(2n+1). %Y A163919 See also A163909. %K A163919 nonn %O A163919 0,3 %A A163919 _Antti Karttunen_, Sep 19 2009