Irregular chromatic number for hypercube graph and its variants

The attractive properties of the hypercube graph such as its diameter, good connectivity, and symmetry have made it a popular topology for the design of multi-computer interconnection networks. Efforts to improve some of these properties have led to the evolution of hypercube variants. Let c be the proper coloring of graph G, where the neighboring vertices will get individual colors. Coloring c is irregular if distinct vertices have distinct color codes and the least number of colors that ought to receive an irregular coloring is the irregular chromatic number, chi(ir) (G). In this paper, we discuss the irregular coloring and find the irregular chromatic number for the hypercube graph Q(n) and some of its variants using binomial coefficients for the Locally twisted cube graph LTQ(n), Crossed cube graph CQ(n) and two types of Fractal cubic network graph FCNG(1)(k) and FCNG(2)(k).