Generating function
$$U_{1235}(x, y) = \frac{\left(1 - \sqrt{1 - 4 y}\right) \left(\frac{x \left(1 - \sqrt{1 - 4 y}\right)}{2 y} + 1\right)^{3}}{2 y}$$
Explicit formula
$$T_{1235}(n, m, k) = \frac{\left(k + n\right) {\binom{3 k}{n}} {\binom{k + 2 m + n - 1}{m}}}{k + m + n}$$
1 | 1 | 2 | 5 | 14 | 42 | 132 |
3 | 6 | 15 | 42 | 126 | 396 | 1287 |
3 | 9 | 27 | 84 | 27 | 891 | 3003 |
1 | 4 | 14 | 48 | 165 | 572 | 2002 |
0 | 0 | 0 | 0 | 0 | 0 | 0 |
0 | 0 | 0 | 0 | 0 | 0 | 0 |
0 | 0 | 0 | 0 | 0 | 0 | 0 |
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