$$U_{397}(x, y) = - \frac{\sqrt{\frac{4 x}{\sqrt{1 - 4 y}} + \frac{1}{1 - 4 y}}}{2} + \frac{1}{2 \sqrt{1 - 4 y}}$$

$$T_{397}(n, m, k) = \begin{cases}0&\text{if n<k} ,\ \\- \frac{4^{m} k {\binom{k - n - 1}{n - 1}} {\binom{\frac{k}{2} + m - \frac{n}{2} - 1}{m}}}{n} \end{cases} $$