A113385 Column 0 of triangle A113384.

1, 4, 22, 212, 3255, 70777, 2022897, 72375484, 3130502129, 159476810183, 9376968779265, 626244735454991, 46892450411406465, 3894861818247549265, 355651177699555693544, 35432761283736539730108

Offset: 0

Author

Paul D. Hanna, Nov 14 2005

Keywords

• nonn

Crossrefs

Cf. A113381, A113384, A113386 (column 1).

Programs

PARI

a(n)=local(A,B);A=Mat(1);for(m=2,n+1,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); (matrix(#A,#A,r,c,if(r>=c,(A^(3*c-1))[r-c+1,1]))^2)[n+1,1]

Formula

A113384 equals the matrix square of A113381, which has the property: column k of A113381^2 = column 0 of A113381^(3*k+2) for k>=0.