A134525 Column 2 of triangle T=A134523, also equals column 0 of the matrix power T^6, where column k of T = column 0 of matrix power T^{(k+1)(k+2)/2} for k>=0.

1, 6, 51, 636, 11406, 284541, 9580386, 424183235, 24153149813, 1735098195632, 154672986360369, 16865030992205590, 2221033362344695926, 349359800218878205297, 64988052594622640286645

Offset

0,2

Links

Table of n, a(n) for n=0..14.

Prog

(PARI) a(n)=local(A, B); A=matrix(1, 1); A[1, 1]=1; for(m=2, n+3, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 || j==i || j>m-1, B[i, j]=1, if(j==1, B[i, 1]=1, B[i, j]=(A^(j*(j+1)/2))[i-j+1, 1])); )); A=B); A[n+3, 3]

Crossrefs

Cf. A134523 (triangle); other columns: A134524, A134526.

Sequence in context: A304185 A215003 A356925 * A125865 A210810 A134276

Adjacent sequences: A134522 A134523 A134524 * A134526 A134527 A134528

Keyword

nonn

Author

Paul D. Hanna, Nov 15 2007

Status

approved