Pyramid #1006
Pyramid #1007
Pyramid #1008
Generating function
$$U_{1007}(x, y) = \left(x + 1\right)^{2} \left(y + 1\right)^{2}$$
Explicit formula
$$T_{1007}(n, m, k) = {\binom{2 k}{m}} {\binom{2 k}{n}}$$
Data table
1 2 1 0 0 0 0
2 4 2 0 0 0 0
1 2 1 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
Related
Pyramid #803: Right on x
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