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 A135082 #2 Mar 30 2012 18:37:07
%S A135082 1,2,7,40,326,3492,46558,744320,13889080,296459376,7125938790,
%T A135082 190502850972,5607258255032,180198503713952,6278311585490032,
%U A135082 235730921392184452,9489040823468191328,407662178549724426176
%N A135082 Column 1 of triangle A135080.
%C A135082 Triangle A135080 transforms diagonals in the table of coefficients of successive self-compositions of x+x^2 (cf. A122888).
%o A135082 (PARI) {a(n)=local(F=x,M,N,P); M=matrix(n+3,n+3,r,c,F=x;for(i=1,r+c-2,F=subst(F,x,x+x^2+x*O(x^(n+3))));polcoeff(F,c)); N=matrix(n+2,n+2,r,c,M[r,c]);P=matrix(n+2,n+2,r,c,M[r+1,c]);(P~*N~^-1)[n+2,2]}
%Y A135082 Cf. A135080 (triangle); other columns: A135081, A135083.
%K A135082 nonn
%O A135082 0,2
%A A135082 _Paul D. Hanna_, Nov 18 2007