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%I #3 Mar 30 2012 18:37:02
%S 1,1,6,105,3710,219625,19545316,2437990653,405899413380,
%T 87002614878795,23351252019790310,7676367378822833691,
%U 3035533054438876836390,1422385798272704860377055,779768824083518449340320720
%N Column 1 of triangle A126465.
%o (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 Cf. A126465, A126466, A126468; A126469 (row sums).
%K nonn
%O 0,3
%A _Paul D. Hanna_, Dec 27 2006