OFFSET
0,8
COMMENTS
A(10,1) = -10091931669.
FORMULA
Let b(n,k) = 0^n if n*k=0, otherwise b(n,k) = (-1)^n * k * Sum_{j=1..n} (-n+k)^(j-1) * binomial(n,j) * b(n-j,j). Then A(n,k) = b(n,-k).
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, ...
0, 1, 2, 3, 4, 5, ...
0, 5, 12, 21, 32, 45, ...
0, 31, 92, 189, 328, 515, ...
0, 333, 1064, 2373, 4464, 7565, ...
0, 3841, 14112, 34923, 71584, 130725, ...
PROG
(PARI) b(n, k) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, (-n+k)^(j-1)*binomial(n, j)*b(n-j, j)));
a(n, k) = b(n, -k);
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Seiichi Manyama, Jun 16 2025
STATUS
approved
