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A121417
Column 1 of triangle A121416.
8
1, 2, 9, 69, 769, 11346, 208914, 4613976, 118840164, 3496297632, 115638728395, 4246267163601, 171369282105510, 7538270885559264, 358926669220446804, 18389706733665138450, 1008742283718489346668, 58981158542987625464424
OFFSET
0,2
COMMENTS
Also column 1 of square array A136737.
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+2, 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+2, 2])}
CROSSREFS
Cf. A121416 (triangle); other columns: A121418, A121419.
Sequence in context: A319285 A316652 A330471 * A232549 A369778 A284762
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 22 2006
EXTENSIONS
Edited by N. J. A. Sloane, Oct 30 2008 at the suggestion of R. J. Mathar
STATUS
approved