First and Second Zagreb Coindices for Chains of Cycles

AbstractThe graphs which are used in this paper are simple, finite and undirected. The first and second Zagreb indices for every non-adjacent vertices (also called first and second Zagreb coindices) are dependent only on the non-adjacent vertices degrees which interspersed the operations of addition and multiplication, respectively, for the degrees of non-adjacent vertices. The number of the edges incident on vertex v in a graph G is called the degree of a vertex v and the two vertices u and v are non-adjacent if its no common edge between them. In this paper, we found the first and second Zagreb coindices of chains of even cycles and also, gave some examples.