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 A126466 #3 Mar 30 2012 18:37:02
%S A126466 1,1,3,33,855,40475,3039204,331630320,49563943161,9722245517970,
%T A126466 2423526680920125,748560249534719259,280702726068079355157,
%U A126466 125661789748507921799800,66215986172320048509110050
%N A126466 Column 0 of triangle A126465.
%o A126466 (PARI) {a(n)=local(M=matrix(n+1,n+1,r,c,if(r>=c,binomial((r-1)*r*(r+1)/3!-(c-1)*c*(c+1)/3!,r-c))), N=matrix(n+1,n+1,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+1,1]}
%Y A126466 Cf. A126465, A126467, A126468; A126469 (row sums).
%K A126466 nonn
%O A126466 0,3
%A A126466 _Paul D. Hanna_, Dec 27 2006