$$U_{65}(x, y) = \frac{\left(1 - \sqrt{1 - 4 y}\right) \left(x + 1\right)}{2 y}$$

$$T_{65}(n, m, k) = \frac{k {\binom{k}{n}} {\binom{k + 2 m - 1}{m}}}{k + m}$$