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A121420
Matrix cube of triangle A121412.
12
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, 1891371807, 197354133, 17645187
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