A323663 Square array A(n,k), n >= 1, k >= 1, read by antidiagonals, where A(n,k) is Sum_{j=1..n} binomial(j*k, k).
1, 1, 3, 1, 7, 6, 1, 21, 22, 10, 1, 71, 105, 50, 15, 1, 253, 566, 325, 95, 21, 1, 925, 3256, 2386, 780, 161, 28, 1, 3433, 19489, 18760, 7231, 1596, 252, 36, 1, 12871, 119713, 154085, 71890, 17857, 2926, 372, 45, 1, 48621, 748342, 1303753, 747860, 214396, 38332, 4950, 525, 55
Offset: 1
Examples
Square array begins:
1, 1, 1, 1, 1, 1, ...
3, 7, 21, 71, 253, 925, ...
6, 22, 105, 566, 3256, 19489, ...
10, 50, 325, 2386, 18760, 154085, ...
15, 95, 780, 7231, 71890, 747860, ...
21, 161, 1596, 17857, 214396, 2695652, ...
28, 252, 2926, 38332, 539028, 7941438, ...
36, 372, 4950, 74292, 1197036, 20212950, ...
Links
- Seiichi Manyama, Antidiagonals n = 1..140, flattened