$$U_{164}(x, y) = \frac{- x^{3} + 3 x^{2} - 3 x + \left(x - 1\right) \sqrt{x^{4} - 4 x^{3} + 6 x^{2} - 4 x + y \left(4 x - 4\right) + 1} + 1}{2 y}$$

$$T_{164}(n, m, k) = \frac{k {\binom{k + 2 m - 1}{m}} {\binom{3 m + n - 1}{n}}}{k + m}$$