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A121420

Matrix cube of triangle A121412.

1, 3, 1, 12, 3, 1, 76, 15, 3, 1, 711, 118, 18, 3, 1, 9054, 1317, 169, 21, 3, 1, 147471, 19311, 2190, 229, 24, 3, 1, 2938176, 352636, 36360, 3378, 298, 27, 3, 1, 69328365, 7722840, 737051, 62655, 4929, 376, 30, 3, 1, 1891371807, 197354133, 17645187

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OFFSET

0,2

COMMENTS

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..47.

EXAMPLE

Triangle begins:

3, 1;

12, 3, 1;

76, 15, 3, 1;

711, 118, 18, 3, 1;

9054, 1317, 169, 21, 3, 1;

147471, 19311, 2190, 229, 24, 3, 1;

2938176, 352636, 36360, 3378, 298, 27, 3, 1;

69328365, 7722840, 737051, 62655, 4929, 376, 30, 3, 1; ...

PROG

(PARI) {T(n, k)=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^3)[n+1, k+1])}

CROSSREFS

Cf. A121412, A121416; A101479; columns: A121421, A121422, A121423.

Sequence in context: A124572 A144880 A144881 * A366892 A283085 A288403

Adjacent sequences: A121417 A121418 A121419 * A121421 A121422 A121423

KEYWORD

nonn,tabl

AUTHOR

Paul D. Hanna, Aug 23 2006

STATUS

approved

URL: https://oeis.org/A121420

⇱ A121420 - OEIS