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 A126468 #3 Mar 30 2012 18:37:02
%S A126468 1,1,10,255,11935,879571,93365328,13464554610,2531141851260,
%T A126468 601339958510170,176255315943299736,62514948119465302825,
%U A126468 26407795709641456484010,13109371824722841349352160
%N A126468 Column 2 of triangle A126465.
%o A126468 (PARI) {a(n)=local(M=matrix(n+3,n+3,r,c,if(r>=c,binomial((r-1)*r*(r+1)/3!-(c-1)*c*(c+1)/3!,r-c))), N=matrix(n+3,n+3,r,c,if(r>=c,binomial((r-1)*r*(r+1)/3!-(c-1)*c*(c+1)/3!+1,r-c)))); (N*M^-1)[n+3,3]}
%Y A126468 Cf. A126465, A126466, A126467; A126469 (row sums).
%K A126468 nonn
%O A126468 0,3
%A A126468 _Paul D. Hanna_, Dec 27 2006