cp's OEIS Frontend

A113090 Triangle T, read by rows, equal to the matrix cube of triangle A113084, which satisfies the recurrence: A113084(n,k) = [A113084^3](n-1,k-1) + [A113084^3](n-1,k).

%I A113090 #3 Mar 30 2012 18:36:51
%S A113090 1,3,1,21,12,1,331,255,39,1,11973,11326,2442,120,1,1030091,1136709,
%T A113090 310864,22206,363,1,218626341,272246616,89081163,8266954,199839,1092,
%U A113090 1,118038692523,162043308555,61099562421,6923071251,220482175,1796349
%N A113090 Triangle T, read by rows, equal to the matrix cube of triangle A113084, which satisfies the recurrence: A113084(n,k) = [A113084^3](n-1,k-1) + [A113084^3](n-1,k).
%e A113090 Triangle begins:
%e A113090 1;
%e A113090 3,1;
%e A113090 21,12,1;
%e A113090 331,255,39,1;
%e A113090 11973,11326,2442,120,1;
%e A113090 1030091,1136709,310864,22206,363,1;
%e A113090 218626341,272246616,89081163,8266954,199839,1092,1; ...
%o A113090 (PARI) {T(n,k)=local(M=matrix(n+1,n+1));for(r=1,n+1, for(c=1,r, M[r,c]=if(r==c,1,if(c>1,(M^3)[r-1,c-1])+(M^3)[r-1,c]))); return((M^3)[n+1,k+1])}
%Y A113090 Cf. A113084, A113081, A113091 (column 1).
%K A113090 nonn,tabl
%O A113090 0,2
%A A113090 _Paul D. Hanna_, Oct 14 2005