$$U_{286}(x, y) = - \frac{2 \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{x}}{2} \right)}}{3} \right)}}{- \sqrt{3} \sqrt{x} + 2 y \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{x}}{2} \right)}}{3} \right)}}$$

$$T_{286}(n, m, k) = \frac{k {\binom{k + m}{m}} {\binom{k + m + 3 n - 1}{n}}}{k + m + 2 n}$$