$$U_{112}(x, y) = \frac{2}{y + \sqrt{- 4 x + y^{2} - 2 y + 1} + 1}$$

$$T_{112}(n, m, k) = \begin{cases}1&\text{if n=0 and m=0} ,\ \\\frac{k {\binom{m + n}{n}} {\binom{k + m + 2 n - 1}{n - 1}}}{m + n} \end{cases} $$