Pyramid #259
Pyramid #260
Pyramid #261
Generating function
$$U_{260}(x, y) = \frac{- 2 y - \sqrt{1 - 4 y} + 1}{y^{2} \left(2 - 2 x\right)}$$
Explicit formula
$$T_{260}(n, m, k) = \frac{k {\binom{2 k + 2 m}{m}} {\binom{k + n - 1}{n}}}{k + m}$$
Data table
1 2 5 14 42 132 429
1 2 5 14 42 132 429
1 2 5 14 42 132 429
1 2 5 14 42 132 429
1 2 5 14 42 132 429
1 2 5 14 42 132 429
1 2 5 14 42 132 429
Related
Pyramid #222: Change x y
Pyramid #259: Left on x
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