Pyramid #309
Generating function
$$U_{309}(x, y) = \frac{- 2 x y^{2} + 2 y + \sqrt{1 - 4 y} - 1}{y \left(\sqrt{1 - 4 y} - 1\right)}$$
Explicit formula
$$T_{309}(n, m, k) = \begin{cases}{\binom{k}{n}}&\text{if m=0} ,\ \\\frac{\left(-1\right)^{m - 1} \left(k - 2 n\right) {\binom{k}{n}} {\binom{- k - m + 2 n - 1}{m - 1}}}{m} \end{cases} $$
Data table
1 1 2 5 14 42 132
1 -1 -1 -2 -5 -14 -42
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
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