$$U_{1396}(x, y) = \frac{\frac{y}{\left(1 - x\right)^{3}} + 1}{\left(1 - x\right)^{3}}$$

$$T_{1396}(n, m, k) = {\binom{k}{m}} {\binom{3 k + 3 m + n - 1}{n}}$$