Incidence coloring of the squares of some graphs

The incidence chromatic number of GG, denoted by χi(G)χi(G), is the least number of colors such that GG has an incidence coloring. In this paper, we determine the incidence chromatic number of the powers of paths, trees, which are min{n,2k+1}min{n,2k+1}, and Δ(T2)+1Δ(T2)+1, respectively. For the square of a Halin graph, we give an upper bound of its incidence chromatic number.