$$U_{305}(x, y) = \frac{\sqrt{3} \left(1 - \sqrt{1 - 4 x}\right) \sin{\left(\frac{\operatorname{asin}{\left(\frac{3 \sqrt{3} \sqrt{y}}{2} \right)}}{3} \right)}}{3 x \sqrt{y}}$$

$$T_{305}(n, m, k) = \frac{k^{2} {\binom{k + 3 m - 1}{m}} {\binom{k + 2 n - 1}{n}}}{\left(k + 2 m\right) \left(k + n\right)}$$