$$U_{245}(x, y) = \frac{x^{2} + y^{2}}{1 - y}$$

$$T_{245}(n, m, k) = \frac{\left(\left(-1\right)^{n} + 1\right) {\binom{k}{k - \frac{n}{2}}} {\binom{- k + m + n - 1}{- 2 k + m + n}}}{2}$$