Pyramid #333
Generating function
$$U_{333}(x, y) = - \frac{\left(\sqrt{4 y + 1} + 1\right)^{2}}{4 x - 2 \sqrt{4 y + 1} - 2}$$
Explicit formula
$$T_{333}(n, m, k) = \begin{cases}{\binom{k + n - 1}{n}}&\text{if m=0} ,\ \\\frac{\left(-1\right)^{m - 1} \left(k - n\right) {\binom{k + n - 1}{n}} {\binom{- k + 2 m + n - 1}{m - 1}}}{m} \end{cases} $$
Data table
1 1 -1 2 -5 14 -42
1 0 0 0 0 0 0
1 -1 2 -5 14 -42 132
1 -2 5 -14 42 -132 429
1 -3 9 -28 9 -297 1001
1 -4 14 -48 165 -572 2002
1 -5 2 -75 275 -1001 364
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