H- and H2- cordial labeling of graphs in the context of some graph operations on crown graph

The concept of H − cordial graphs is introduced by Ibrahim Cahit in 1996. Ibrahim Cahit used the symbol H to represent Hadamard Matrices. He claims that H − cordial graphs can be useful to construct Hadamard matrices since any n x n Hadamard matrix gives an H − cordial labeling for the bipartite graph. In this paper we investigate H − and H 2 − cordial graphs obtained by duplication of a vertex, duplication of a vertex by a new edge and duplication of an edge by a new vertex in some graph elements on crown graph.