Pyramid #588
Generating function
$$U_{588}(x, y) = - \frac{2 \sqrt{3} \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{y}}{2} \right)}}{3} \right)}}{3 \sqrt{y} \left(\frac{8 \sqrt{3} x \sin^{3}{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{y}}{2} \right)}}{3} \right)}}{9 y^{\frac{3}{2}}} - 1\right)}$$
Explicit formula
$$T_{588}(n, m, k) = \frac{\left(k + 3 n\right) {\binom{k + n - 1}{n}} {\binom{k + 3 m + 3 n - 1}{m}}}{k + 2 m + 3 n}$$
Data table
1 1 3 12 55 273 1428
1 4 18 88 455 2448 13566
1 7 42 245 1428 8379 49588
1 1 75 51 3325 21252 13455
1 13 117 91 6578 4563 308763
1 16 168 1472 117 87696 632896
1 19 228 2223 19285 155496 1193808
Export
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