$$U_{435}(x, y) = \frac{- x^{2} + 2 x - 1}{- x^{4} + 4 x^{3} - 6 x^{2} + 4 x + y - 1}$$

$$T_{435}(n, m, k) = \frac{k {\binom{k + m}{m}} {\binom{2 k + 4 m + n - 1}{n}}}{k + m}$$