Pyramid #6
Pyramid #7
Pyramid #8
Generating function
$$U_{7}(x, y) = \left(x + 1\right) \left(x + y\right)$$
Explicit formula
$$T_{7}(n, m, k) = {\binom{k}{m}} {\binom{k}{- k + m + n}}$$
Data table
0 1 0 0 0 0 0
1 1 0 0 0 0 0
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 0 0
Related
Pyramid #8: Change x y
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