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
$$T_{1235}(n, m, k) = \frac{\left(k + n\right) {\binom{3 k}{n}} {\binom{k + 2 m + n - 1}{m}}}{k + m + n}$$
Data table
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
Related
Export
expand_less