Generating function
$$U_{1176}(x, y) = \frac{64 y^{9} \left(1 - \sqrt{- \frac{x \left(1 - \sqrt{1 - 4 y}\right)^{3}}{2 y^{3}} + 1}\right)^{3}}{x^{3} \left(1 - \sqrt{1 - 4 y}\right)^{9}}$$
Explicit formula
$$T_{1176}(n, m, k) = \frac{9 k n {\binom{3 k + 2 n - 1}{n}} {\binom{2 m + 3 n - 1}{m}}}{\left(3 k + n\right) \left(m + 3 n\right)}$$
Data table
nan 0 0 0 0 0 0
3 9 27 84 27 891 3003
9 54 243 99 3861 14742 55692
28 252 1512 7644 3528 154224 651168
9 108 81 4896 26163 129276 605682
297 4455 40095 28215 1715175 9467766 4884165
1001 18018 189189 1519518 1036035 6324318 356621265
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