Pyramid #19
Generating function
$$U_{19}(x, y) = - \frac{1}{x + y - 1}$$
Explicit formula
$$T_{19}(n, m, k) = {\binom{k + n - 1}{n}} {\binom{k + m + n - 1}{m}}$$
Data table
1 1 1 1 1 1 1
1 2 3 4 5 6 7
1 3 6 1 15 21 28
1 4 1 2 35 56 84
1 5 15 35 7 126 21
1 6 21 56 126 252 462
1 7 28 84 21 462 924
Export
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