$$U_{749}(x, y) = \frac{y^{3} \left(- \frac{2 x \left(1 - \sqrt{1 - 4 y}\right)^{2}}{y^{2}} - 4 \sqrt{- \frac{x \left(1 - \sqrt{1 - 4 y}\right)^{2}}{y^{2}} + 1} + 4\right)}{x^{2} \left(1 - \sqrt{1 - 4 y}\right)^{3}}$$

$$T_{749}(n, m, k) = \frac{k \left(k + 2 n\right) {\binom{2 k + 2 n}{n}} {\binom{k + 2 m + 2 n - 1}{m}}}{\left(k + n\right) \left(k + m + 2 n\right)}$$