A113376 - OEIS

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

%S 1,8,84,1296,27850,784146,27630378,1177691946,59169833470,

%T 3434258845248,226594550768662,16775755397765720,1378646430074005827,

%U 124636321499378130839,12300850874338422058685

%N Column 1 of triangle A113374, also equals column 0 of A113381^4.

%F A113374 equals the matrix square of A113370, which has the property: column k of A113370^2 = column 0 of A113381^(3*k+1) 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^2)[n+2,2]

%Y Cf. A113374, A113375 (column 0), A113377 (column 2).

%K nonn

%O 0,2

%A _Paul D. Hanna_, Nov 14 2005