The Zagreb indices of graphs based on four new operations related to the lexicographic product

摘要

For a (molecular) graph, the first Zagreb index M1 is the sum of squares of the degrees of vertices, and the second Zagreb index M2 is the sum of the products of the degrees of pairs of adjacent vertices. In this work, we study the first and second Zagreb indices of graphs based on four new operations related to the lexicographic product, subdivision and total graph.