$$U_{49}(x, y) = \frac{x^{2} - 2 x - \sqrt{x^{4} - 4 x^{3} + 6 x^{2} - 4 x + y \left(4 x - 4\right) + 1} + 1}{2 y}$$

$$T_{49}(n, m, k) = \begin{cases}\frac{k {\binom{k + 2 m - 1}{m}} {\binom{k + 3 m + n - 1}{n}}}{k + m}&\text{if m=0} ,\ \\\frac{k {\binom{k + 2 m - 1}{m}} {\binom{k + 3 m + n - 1}{n}}}{k + m} \end{cases} $$