Generating function
$$U_{1043}(x, y) = \frac{1}{\left(1 - x\right)^{3} \left(1 - y\right)}$$
Explicit formula
$$T_{1043}(n, m, k) = {\binom{k + m - 1}{m}} {\binom{3 k + n - 1}{n}}$$
Data table
1 1 1 1 1 1 1
3 3 3 3 3 3 3
6 6 6 6 6 6 6
1 1 1 1 1 1 1
15 15 15 15 15 15 15
21 21 21 21 21 21 21
28 28 28 28 28 28 28
Export
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