Pyramid #512
Generating function
$$U_{512}(x, y) = - \frac{\left(y + 1\right)^{3}}{x - \left(y + 1\right)^{2}}$$
Explicit formula
$$T_{512}(n, m, k) = {\binom{k - 2 n}{m}} {\binom{k + n - 1}{n}}$$
Data table
1 1 0 0 0 0 0
1 -1 1 -1 1 -1 1
1 -3 6 -1 15 -21 28
1 -5 15 -35 7 -126 21
1 -7 28 -84 21 -462 924
1 -9 45 -165 495 -1287 3003
1 -11 66 -286 1001 -3003 8008
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