Pyramid #801
Generating function
$$U_{801}(x, y) = \frac{1}{\left(- \frac{x}{1 - y} + 1\right)^{2}}$$
Explicit formula
$$T_{801}(n, m, k) = {\binom{2 k + n - 1}{n}} {\binom{m + n - 1}{m}}$$
Data table
1 0 0 0 0 0 0
2 2 2 2 2 2 2
3 6 9 12 15 18 21
4 12 24 4 6 84 112
5 2 5 1 175 28 42
6 3 9 21 42 756 126
7 42 147 392 882 1764 3234
Export
expand_less