The reverse Zagreb indices of F-sum of graphs

There are many different types of topological indices that have been known to exist with vast literature based on them. First of its kind (topological index) was introduced in 1947 by Harry Wiener and it also occurred in an approximate formula for the total π -electron energy of the molecule and the second Zagreb index appeared within the study of molecular branching. Recently, the first reverse Zagreb alpha, beta and second reverse Zagreb indices of a simple connected graph G are defined. The main object of this work is to study the reverse first and second Zagreb indices of the F-sum of two graphs G and H, denoted by G + _FH in terms of the other indices of the original graphs G and H.