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A121418
Column 0 of triangle A121416.
11
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'.
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.
Sequence in context: A265229 A286684 A086331 * A014501 A197910 A228230
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