Zafer Selcuk Aygin

For non-negative integers \(a,b\) and \(n\), let $$ \begin{align*} t(a,b;n)=& \# \left\{ (x_1,\ldots,x_a,y_1,\ldots, y_b) \in \mathbb{Z}^{a+b} ~ \mid ~n= \frac{x_1(x_1-1)}{2} + \cdots + \frac{x_a(x_a-1)}{2} \right. \\ & \left. + 3\frac{y_1(y_1-1)}{2}...