cp's OEIS Frontend

A135889 Column 0 of triangle A135888, which equals the matrix cube of triangle A135880; also equals column 1 of triangle A135894.

%I A135889 #2 Mar 30 2012 18:37:08
%S A135889 1,3,12,63,421,3472,34380,399463,5344770,81097517,1377986373,
%T A135889 25947738574,536726987593,12104879913657,295754724799758,
%U A135889 7784814503249896,219682110287448760,6617691928179590112
%N A135889 Column 0 of triangle A135888, which equals the matrix cube of triangle A135880; also equals column 1 of triangle A135894.
%o A135889 (PARI) {a(n)=local(P=Mat(1),R,PShR);if(n==0,1,for(i=0,n, PShR=matrix(#P,#P, r,c, if(r>=c,if(r==c,1,if(c==1,0,P[r-1,c-1]))));R=P*PShR; R=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,R[r,c], if(c==1,(P^2)[ #P,1],(P^(2*c-1))[r-c+1,1])))); P=matrix(#R, #R, r,c, if(r>=c, if(r<#R,P[r,c], (R^c)[r-c+1,1]))));(P^3)[n+1,1])}
%Y A135889 Cf. A135888, A135890; A135880, A135894.
%K A135889 nonn
%O A135889 0,2
%A A135889 _Paul D. Hanna_, Dec 15 2007