$$U_{1138}(x, y) = \frac{1}{\left(- \frac{x \left(1 - \sqrt{1 - 4 y}\right)^{2}}{4 y^{2}} + 1\right)^{2}}$$

$$T_{1138}(n, m, k) = \frac{2 n {\binom{2 k + n - 1}{n}} {\binom{2 m + 2 n - 1}{m}}}{m + 2 n}$$