A361600 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = n! * Sum_{j=0..n} binomial(n+(k-1)*j,k*j)/j!.
1, 1, 2, 1, 2, 5, 1, 2, 7, 16, 1, 2, 9, 34, 65, 1, 2, 11, 58, 209, 326, 1, 2, 13, 88, 473, 1546, 1957, 1, 2, 15, 124, 881, 4626, 13327, 13700, 1, 2, 17, 166, 1457, 10526, 52537, 130922, 109601, 1, 2, 19, 214, 2225, 20326, 145867, 677594, 1441729, 986410
Offset: 0
Examples
Square array begins: 1, 1, 1, 1, 1, 1, ... 2, 2, 2, 2, 2, 2, ... 5, 7, 9, 11, 13, 15, ... 16, 34, 58, 88, 124, 166, ... 65, 209, 473, 881, 1457, 2225, ... 326, 1546, 4626, 10526, 20326, 35226, ...
Links
- Seiichi Manyama, Antidiagonals n = 0..139, flattened
Crossrefs
Programs
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PARI
T(n, k) = n!*sum(j=0, n, binomial(n+(k-1)*j, k*j)/j!);
Formula
E.g.f. of column k: exp( x/(1 - x)^k ) / (1-x).
T(n,k) = Sum_{j=0..n} (n+(k-1)*j)!/(k*j)! * binomial(n,j).