Pyramid #851
Generating function
$$U_{851}(x, y) = \frac{- 2 x - \sqrt{4 x + 1} - 1}{2 y - 2}$$
Explicit formula
$$T_{851}(n, m, k) = \begin{cases}{\binom{k + m - 1}{m}}&\text{if n = 0} ,\ \\\frac{2 \left(-1\right)^{n - 1} k {\binom{- 2 k + 2 n - 1}{n - 1}} {\binom{k + m - 1}{m}}}{n}&\text{if n > 0} \end{cases} $$
Data table
1 1 1 1 1 1 1
2 2 2 2 2 2 2
-1 -1 -1 -1 -1 -1 -1
2 2 2 2 2 2 2
-5 -5 -5 -5 -5 -5 -5
14 14 14 14 14 14 14
-42 -42 -42 -42 -42 -42 -42
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