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;
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
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Aug 23 2006
STATUS
approved