OFFSET
0,2
COMMENTS
Row n of triangle T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.
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
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Aug 22 2006
STATUS
approved