A121418 Column 0 of triangle A121416.

1, 2, 7, 43, 403, 5188, 85569, 1725291, 41145705, 1133047596, 35377360292, 1234796503280, 47636225803285, 2012509471127885, 92398547122062997, 4580472438441602301, 243822925502110419105, 13870297863425823346284

Offset

0,2

Comments

Also column 1 of square array A136733.

A121416 is the matrix square of triangle A121412; row n of triangle T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

Links

Table of n, a(n) for n=0..17.

Prog

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^2)[n+1, 1])}

Crossrefs

Cf. A121416 (triangle); other columns: A121418, A121419.

Cf. A136733; A101483, A121421; A121425.

Sequence in context: A265229 A286684 A086331 * A014501 A197910 A228230

Adjacent sequences: A121415 A121416 A121417 * A121419 A121420 A121421

Keyword

nonn

Author

Paul D. Hanna, Aug 22 2006, Jan 19 2008

Extensions

Edited by N. J. A. Sloane, Oct 30 2008 at the suggestion of R. J. Mathar

Status

approved