A121416 Matrix square of triangle A121412.

1, 2, 1, 7, 2, 1, 43, 9, 2, 1, 403, 69, 11, 2, 1, 5188, 769, 101, 13, 2, 1, 85569, 11346, 1305, 139, 15, 2, 1, 1725291, 208914, 21745, 2043, 183, 17, 2, 1, 41145705, 4613976, 443329, 37971, 3015, 233, 19, 2, 1, 1133047596, 118840164, 10679494, 850260

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..48.

Example

Triangle begins:
1;
2, 1;
7, 2, 1;
43, 9, 2, 1;
403, 69, 11, 2, 1;
5188, 769, 101, 13, 2, 1;
85569, 11346, 1305, 139, 15, 2, 1;
1725291, 208914, 21745, 2043, 183, 17, 2, 1;
41145705, 4613976, 443329, 37971, 3015, 233, 19, 2, 1;
1133047596, 118840164, 10679494, 850260, 61860, 4253, 289, 21, 2, 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^2)[n+1, k+1])}

Crossrefs

Cf. A121412, A121420; A101479; columns: A121417, A121418, A121419.

Sequence in context: A205945 A124392 A144446 * A317547 A089329 A213053

Adjacent sequences: A121413 A121414 A121415 * A121417 A121418 A121419

Keyword

nonn,tabl

Author

Paul D. Hanna, Aug 22 2006

Status

approved