$$U_{1458}(x, y) = \frac{\left(1 - y\right)^{5} \left(- \frac{2 x}{\left(1 - y\right)^{3}} - \sqrt{- \frac{4 x}{\left(1 - y\right)^{3}} + 1} + 1\right)}{2 x^{2}}$$

$$T_{1458}(n, m, k) = \frac{k {\binom{2 k + 2 n}{n}} {\binom{k + m + 3 n - 1}{m}}}{k + n}$$