$$U_{389}(x, y) = \frac{1 - \sqrt{- 4 x y^{4} - 16 x y^{3} - 24 x y^{2} - 16 x y - 4 x + 1}}{2 x y^{2} + 4 x y + 2 x}$$

$$T_{389}(n, m, k) = \frac{k {\binom{2 k + 4 n}{m}} {\binom{k + 2 n - 1}{n}}}{k + n}$$