$$U_{342}(x, y) = \frac{2 y \left(x + \frac{1 - \sqrt{1 - 4 y}}{2 y}\right)^{2}}{1 - \sqrt{1 - 4 y}}$$

$$T_{342}(n, m, k) = \begin{cases}{\binom{2 k}{n}}&\text{if m=0} ,\ \\\frac{\left(-1\right)^{m - 1} \left(k - n\right) {\binom{2 k}{n}} {\binom{- k - m + n - 1}{m - 1}}}{m} \end{cases} $$