A113375 Column 0 of triangle A113374, also equals column 0 of A113381.

1, 2, 6, 37, 429, 7629, 185776, 5817106, 224558216, 10362978307, 558458382528, 34504326965326, 2408502186081117, 187672037804601000, 16162473554575583148, 1525578320627987001344, 156704538246796929248712

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Formula

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.

Prog

(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); (A^2)[n+1, 1]

Crossrefs

Cf. A113374, A113376 (column 1), A113377 (column 2).

Sequence in context: A014052 A014056 A241300 * A117266 A259437 A202737

Adjacent sequences: A113372 A113373 A113374 * A113376 A113377 A113378

Keyword

nonn

Author

Paul D. Hanna, Nov 14 2005

Status

approved