$$U_{170}(x, y) = \frac{- 2 x y - x - \sqrt{x^{2} - 4 x y - 2 x + 1} + 1}{2 x^{2} y}$$

$$T_{170}(n, m, k) = \frac{k {\binom{k + n}{m}} {\binom{k + m + n}{n}}}{k + n}$$