zagreb indices belong to better known and better researched topological indices. weinvestigate here their ability to discriminate among benzenoid graphs and arrive at some quiteunexpected conclusions. along the way we establish tight (and sometimes sharp) lower andupper bounds on various classes of benzenoids.

The study of the maximum and minimal characteristics graphs is focus significant field mathematics known as extreme graph theory. Finding biggest or smallest that meet specified criteria main goal this discipline. There are several applications extremal theory in various fields, including computer science, physics, chemistry. Some important include: Computer networking, social chemistry physics...

The forgotten topological index of a molecular graph $G$ is defined as $F(G)=sum_{vin V(G)}d^{3}(v)$, where $d(u)$ denotes the degree of vertex $u$ in $G$. The first through the sixth smallest forgotten indices among all trees, the first through the third smallest forgotten indices among all connected graph with cyclomatic number $gamma=1,2$, the first through<br /...

We investigate the Zagreb index, one of the topological indices, of random recursive trees in this paper. Through a recurrence equation, the first two moments of Zn, the Zagreb index of a random recursive tree of size n, are obtained. We also show that the random process {Zn − E[Zn], n ≥ 1} is a martingale. Then the asymptotic normality of the Zagreb index of a random recursive tree is given by...

The Zagreb indices are the oldest graph invariants used in mathematical chemistry to predict the chemical phenomena. In this paper we define the multiple versions of Zagreb indices based on degrees of vertices in a given graph and then we compute the first and second extremal graphs for them.

The first general Zagreb index is defined as Mλ 1 (G) = ∑ v∈V (G) dG(v) λ where λ ∈ R − {0, 1}. The case λ = 3, is called F-index. Similarly, reformulated first general Zagreb index is defined in terms of edge-drees as EMλ 1 (G) = ∑ e∈E(G) dG(e) λ and the reformulated F-index is RF (G) = ∑ e∈E(G) dG(e) 3. In this paper, we compute the reformulated F-index for some graph operations.

The similarity of 608 molecular descriptors (including topological and geometrical indices) is measured using correlation coefficients. The computations are based on a library of 10946 diverse compounds. As a result, the second Zagreb index M2 and mwc, the molecular walk count of length 3, were found and proven to be affine dependent: mwc = 2M2.

For a (molecular) graph, the hyper Zagreb index is defined as HM(G) = ∑ uv∈E(G) (dG(u) + dG(v)) 2 and the hyper Zagreb coindex is defined asHM(G) = ∑ uv/ ∈E(G) (dG(u)+dG(v)) 2. In this paper, the hyper Zagreb indices and its coindices of edge corona product graph, double graph and Mycielskian graph are obtained.