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 A126467 #3 Mar 30 2012 18:37:02
%S A126467 1,1,6,105,3710,219625,19545316,2437990653,405899413380,
%T A126467 87002614878795,23351252019790310,7676367378822833691,
%U A126467 3035533054438876836390,1422385798272704860377055,779768824083518449340320720
%N A126467 Column 1 of triangle A126465.
%o A126467 (PARI) {a(n)=local(M=matrix(n+2,n+2,r,c,if(r>=c,binomial((r-1)*r*(r+1)/3!-(c-1)*c*(c+1)/3!,r-c))), N=matrix(n+2,n+2,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+2,2]}
%Y A126467 Cf. A126465, A126466, A126468; A126469 (row sums).
%K A126467 nonn
%O A126467 0,3
%A A126467 _Paul D. Hanna_, Dec 27 2006