$$U_{128}(x, y) = \frac{1}{\sqrt{x^{2} y^{2} - 4 x^{2} y - 2 x y + 1}}$$

$$T_{128}(n, m, k) = \begin{cases}\frac{k {\binom{k + n}{k - 2 m + 2 n}} {\binom{k - m + n}{k}} {\binom{2 k - 2 m + 2 n}{k - m + n}}}{\left(k + n\right) {\binom{2 k}{k}}}&\text{if k odd} ,\ \\\frac{4^{- m + n} k {\binom{k + n}{k - 2 m + 2 n}} {\binom{k - m + n}{k}}}{k + n}&\text{if k even} \end{cases} $$