A113090 Triangle T, read by rows, equal to the matrix cube of triangle A113084, which satisfies the recurrence: A113084(n,k) = [A113084^3](n-1,k-1) + [A113084^3](n-1,k).

1, 3, 1, 21, 12, 1, 331, 255, 39, 1, 11973, 11326, 2442, 120, 1, 1030091, 1136709, 310864, 22206, 363, 1, 218626341, 272246616, 89081163, 8266954, 199839, 1092, 1, 118038692523, 162043308555, 61099562421, 6923071251, 220482175, 1796349

Offset

0,2

Links

Table of n, a(n) for n=0..33.

Example

Triangle begins:
1;
3,1;
21,12,1;
331,255,39,1;
11973,11326,2442,120,1;
1030091,1136709,310864,22206,363,1;
218626341,272246616,89081163,8266954,199839,1092,1; ...

Prog

(PARI) {T(n, k)=local(M=matrix(n+1, n+1)); for(r=1, n+1, for(c=1, r, M[r, c]=if(r==c, 1, if(c>1, (M^3)[r-1, c-1])+(M^3)[r-1, c]))); return((M^3)[n+1, k+1])}

Crossrefs

Cf. A113084, A113081, A113091 (column 1).

Sequence in context: A000369 A225471 A136236 * A223549 A138354 A193632

Adjacent sequences: A113087 A113088 A113089 * A113091 A113092 A113093

Keyword

nonn,tabl

Author

Paul D. Hanna, Oct 14 2005

Status

approved