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 A118926 #3 Mar 30 2012 18:36:57
%S A118926 1,2,7,28,125,598,3007,15708,84585,466954,2632167,15103676,88012801,
%T A118926 519848442,3107443803,18774545752,114527169657,704731976138,
%U A118926 4370943547471,27306560735812,171728169545661,1086605771091766
%N A118926 Invariant column vector V under matrix product A104546*V = V: a(n) = Sum_{k=0,[n/2]} A104546(n,k)*a(k).
%C A118926 Triangle A104546(n,k) = the number of Schroeder paths of length 2n and having k platforms.
%F A118926 Self-convolution of A118927.
%o A118926 (PARI) {a(n)=local(G=1+x+x*O(x^n));if(n==0,1, for(i=0,n,G=1+x*G+x*G*(G+(y-1)*x/(1-x))); sum(k=0,n\2,a(k)*polcoeff(polcoeff(G+y*O(y^k),n,x),k,y)))}
%Y A118926 Cf. A104546, A118927 (self-convolution square-root).
%K A118926 nonn
%O A118926 0,2
%A A118926 _Paul D. Hanna_, May 06 2006