$$U_{134}(x, y) = \left(x + y\right)^{3}$$

$$\delta{(a, b)} = \begin{cases}1&\text{if a = b},\\ 0 \end{cases} $$$$T_{134}(n, m, k) = \delta{\left(3 k,m + n \right)} {\binom{m + n}{m}}$$