login
Column 2 of triangle A113381, also equals column 0 of A113370^8.
2

%I #5 Jun 13 2017 23:23:04

%S 1,8,120,2556,71548,2508528,106427700,5323786728,307710142888,

%T 20222341451124,1491479257952300,122128352186849366,

%U 11002901720698439826,1082337197005046142588,115485905212456384697750

%N Column 2 of triangle A113381, also equals column 0 of A113370^8.

%F Column k of A113381 = column 0 of A113370^(3*k+2) for k>=0.

%o (PARI) a(n)=local(A,B);A=Mat(1);for(m=2,n+2,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(3*j-2))[i-j+1,1]));));A=B);(A^8)[n+1,1]

%Y Cf. A113381, A113375 (column 0), A113382 (column 1), A113370.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Nov 14 2005