Pyramid #860
Generating function
$$U_{860}(x, y) = \frac{2 \sqrt{3} \left(y + 1\right)^{3} \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{x \left(y + 1\right)}}{2} \right)}}{3} \right)}}{3 \sqrt{x \left(y + 1\right)}}$$
Explicit formula
$$T_{860}(n, m, k) = \frac{k {\binom{3 k + n}{m}} {\binom{k + 3 n - 1}{n}}}{k + 2 n}$$
Data table
1 3 3 1 0 0 0
1 4 6 4 1 0 0
3 15 3 3 15 3 0
12 72 18 24 18 72 12
55 385 1155 1925 1925 1155 385
273 2184 7644 15288 1911 15288 7644
1428 12852 51408 119952 179928 179928 119952
Export
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