Pyramid #161
Generating function
$$U_{161}(x, y) = \frac{x - \sqrt{x^{2} - 2 x + 4 y + 1} - 1}{2 x - 2}$$
Explicit formula
$$T_{161}(n, m, k) = \begin{cases}1&\text{if n=0,m=0} ,\ \\0&\text{if m=0} ,\ \\\frac{\left(-1\right)^{m - 1} k {\binom{- k + 2 m - 1}{m - 1}} {\binom{2 m + n - 1}{n}}}{m} \end{cases} $$
Data table
1 1 -1 2 -5 14 -42
0 2 -4 12 -4 14 -504
0 3 -1 42 -18 77 -3276
0 4 -2 112 -6 308 -15288
0 5 -35 252 -165 1001 -5733
0 6 -56 504 -396 28028 -183456
0 7 -84 924 -858 7007 -519792
Export
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