$$U_{538}(x, y) = \frac{\sqrt{3} \left(- 2 y - \sqrt{1 - 4 y} + 1\right) \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{x}}{2} \right)}}{3} \right)}}{3 \sqrt{x} y^{2}}$$

$$T_{538}(n, m, k) = \frac{k^{2} {\binom{2 k + 2 m}{m}} {\binom{k + 3 n - 1}{n}}}{\left(k + m\right) \left(k + 2 n\right)}$$