$$U_{635}(x, y) = \frac{- 2 y - \sqrt{1 - 4 y} + 1}{2 y^{2} \sqrt{1 - 4 x}}$$

$$T_{635}(n, m, k) = \frac{4^{n} k {\binom{2 k + 2 m}{m}} {\binom{\frac{k}{2} + n - 1}{n}}}{k + m}$$