A113377 Column 2 of triangle A113374, also equals column 0 of A113381^7.

1, 14, 252, 5957, 179270, 6641502, 294524076, 15285260326, 911664081027, 61573228385424, 4652227417900405, 389256081747220268, 35759870451009454561, 3580704593280285017869, 388344720309998846243731

Offset

0,2

Links

Table of n, a(n) for n=0..14.

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+3, 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+3, 3]

Crossrefs

Cf. A113374, A113375 (column 0), A113376 (column 1).

Sequence in context: A074815 A280122 A051622 * A318596 A343688 A159516

Adjacent sequences: A113374 A113375 A113376 * A113378 A113379 A113380

Keyword

nonn

Author

Paul D. Hanna, Nov 14 2005

Status

approved