Pyramid #589
Generating function
$$U_{589}(x, y) = \frac{3 \sqrt{3} y^{\frac{3}{2}} \left(1 - \sqrt{- \frac{64 x \sin^{4}{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{y}}{2} \right)}}{3} \right)}}{9 y^{2}} + 1}\right)}{16 x \sin^{3}{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{y}}{2} \right)}}{3} \right)}}$$
Explicit formula
$$T_{589}(n, m, k) = \frac{k \left(k + 4 n\right) {\binom{k + 2 n - 1}{n}} {\binom{k + 3 m + 4 n - 1}{m}}}{\left(k + n\right) \left(k + 2 m + 4 n\right)}$$
Data table
1 1 3 12 55 273 1428
1 5 25 13 7 3876 21945
2 18 126 816 513 31878 19734
5 65 585 455 3289 22815 1543815
14 238 2618 238 194922 1497734 11037488
42 882 11466 119364 109368 9236304 73785474
132 33 495 5808 58905 5428566 4678674
Export
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