Generating function
$$U_{1466}(x, y) = \frac{2 \sqrt{3} \sin{\left(\frac{\arcsin{\left(\frac{3 \sqrt{3} \sqrt{x \left(y + 1\right)^{3}}}{2} \right)}}{3} \right)}}{3 \sqrt{x \left(y + 1\right)^{3}}}$$
Explicit formula
$$T_{1466}(n, m, k) = \frac{k {\binom{3 n}{m}} {\binom{k + 3 n - 1}{n}}}{k + 2 n}$$
Data table
1 0 0 0 0 0 0
1 3 3 1 0 0 0
3 18 45 6 45 18 3
12 108 432 1008 1512 1512 1008
55 66 363 121 27225 4356 5082
273 4095 28665 124215 372645 819819 1366365
1428 25704 218484 1165248 436968 12235104 26509392
Export
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