Quadratic Packing Polynomials on Sectors of $\mathbb{R}^2$
  A polynomial $p(x,y)$ on a region $S$ in the plane is called a packing polynomial if the restriction of $p(x,y)$ to $S\cap \mathbb{Z}^2$ yields a bijection to $\mathbb{N}$. In this paper, we determine all quadratic packing polynomials on rational sectors of $\mathbb{R}^2$. 
Madeline Brandt
math.CO