Reversed Dickson polynomials of the fourth kind over finite fields
  In this paper, we obtain several results on the permutational behavior of the reversed Dickson polynomial $D_{n,3}(1,x)$ of the fourth kind over the finite field ${\mathbb F}_{q}$. Particularly, we present the explicit evaluation of the first moment $\sum_{a\in {\mathbb F}_{q}}D_{n,3}(1,a)$. 
Kaimin Cheng, Shaofang Hong and Xiaoer Qin
math.NT