$$U_{1268}(x, y) = \frac{1 - \sqrt{- \frac{x \left(- 2 y - \sqrt{1 - 4 y} + 1\right)^{2}}{y^{4}} + 1}}{2 x}$$

$$T_{1268}(n, m, k) = \frac{2 k {\binom{k + 2 n - 1}{n}} {\binom{4 k + 2 m + 4 n}{m}}}{2 k + m + 2 n}$$