Generating function
$$U_{1171}(x, y) = \frac{\left(1 - y\right)^{3} \left(1 - \sqrt{- \frac{4 x}{1 - y} + 1}\right)^{3}}{8 x^{3}}$$
Explicit formula
$$T_{1171}(n, m, k) = \frac{3 k {\binom{3 k + 2 n - 1}{n}} {\binom{m + n - 1}{m}}}{3 k + n}$$
Data table
1 0 0 0 0 0 0
3 3 3 3 3 3 3
9 18 27 36 45 54 63
28 84 168 28 42 588 784
9 36 9 18 315 504 756
297 1485 4455 10395 2079 37422 6237
1001 6006 21021 56056 126126 252252 462462
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