OFFSET
0,3
COMMENTS
Row sums form A108292. Main diagonal is A000169(n) = (n+1)^n. Triangle with rows reversed is A108291.
The rows seem to give (up to sign) the coefficients in the expansion of the integer-valued polynomial (1+n*x)*(2+n*x)*...*(n-1+n*x)/(n-1)! in the basis made of the binomial(x+i,i). - F. Chapoton, Nov 01 2022
EXAMPLE
BINOMIAL[1, 9, 9] = {1, 10, 28, 55, 91, 136, 190, 253, ...}.
BINOMIAL[1, 34, 96, 64] = {1, 35, 165, 455, 969, 1771, 2925, ...}.
BINOMIAL[1, 125, 750, 1250, 625] = {1, 126, 1001, 3876, 10626, ...}.
Triangle begins:
1;
1, 2;
1, 9, 9;
1, 34, 96, 64;
1, 125, 750, 1250, 625;
1, 461, 5265, 16470, 19440, 7776;
1, 1715, 35329, 184877, 386561, 352947, 117649;
1, 6434, 232288, 1913408, 6307840, 9863168, 7340032, 2097152; ...
PROG
(PARI) {T(n, k)=local(X=x+x*O(x^k)); polcoeff(sum(j=0, n, binomial(n+n*j+j, n*j+j)*(x/(1+X))^j)/(1+X), k)}
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, May 31 2005
STATUS
approved