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 A130649 #3 Sep 08 2013 13:31:20
%S A130649 1,2,8,42,260,1796,13372,104922,854964,7165500
%N A130649 Generalized ballot transform of generalized Catalan numbers C(2;n)=A064062(n).
%F A130649 a(n)=Sum_{k, 0<=k<=n}A039599(n,k)*A064062(k).
%K A130649 nonn
%O A130649 0,2
%A A130649 _Philippe Deléham_, Jun 20 2007