on harmonious chromatic number of triple star graph

A harmonious coloring of a graph g is a proper vertex coloring of g, in which every pair of colors appears on at most one pair of adjacent vertices and the harmonious chromatic number of graph g is the minimum number of colors needed for the harmonious coloring of g and it is denoted byxh(g).the purpose of this paper is to extend the double star graph [12] and to discuss harmonious coloring for central graph, middle graph and total graph of extended double star graph i.e. triple star graph.