extremal tetracyclic graphs with respect to the first and second zagreb indices

First and Second Zagreb Eccentricity Indices of Thorny Graphs

The Zagreb eccentricity indices are the eccentricity reformulation of the Zagreb indices. Let H be a simple graph. The first Zagreb eccentricity index (E1(H)) is defined to be the summation of squares of the eccentricity of vertices, i.e., E1(H) = ∑u∈V(H) Symmetry 2016, 9, 7; doi: 10.3390/sym9010007 www.mdpi.com/journal/symmetry Article First and Second Zagreb Eccentricity Indices of Thorny Gra...

The First and Second Zagreb Indices, First and Second Zagreb Polynomials of HAC5C6C7[p,q] and HAC5C7[p,q] Nanotubes

Topological indices are numerical parameters of a molecular graph G which characterize its topology. On the other hands, computing the connectivity indices of molecular graphs is an important branch in chemical graph theory. Therefore, we compute First Zagreb index Zg   <span style="font-family: TimesNewRomanPS-Italic...

First and second extremal bipartite graphs with respect to PI index

The Padmakar–Ivan (PI) index of a graph G is defined as the sum of terms [mu(e) + mv(e)] over all edges of G, where e is an edge, connecting the vertices u and v, wheremu(e) is the number of edges of G lying closer to the vertex u than to the vertex v, and where mv(e) is defined analogously. The extremal values of the PI index are determined in the class of connected bipartite graphs with a giv...

Trees, Unicyclic, and Bicyclic Graphs Extremal with Respect to Multiplicative Sum Zagreb Index∗

For a (molecular) graph G with vertex set V (G) and edge set E(G), the first Zagreb index of G is defined as M1(G) = ∑ v∈V (G) dG(v) 2 where dG(v) is the degree of vertex v in G. The alternative expression for M1(G) is ∑ uv∈E(G)(dG(u)+dG(v)). Very recently, Eliasi, Iranmanesh and Gutman [7] introduced a new graphical invariant ∏∗ 1(G) = ∏ uv∈E(G)(dG(u) + dG(v)) as the multiplicative version of ...

The First and Second Zagreb Indices of Generalized Complementary Prisms

The first and second zagreb indices of a graph G are defined as M1(G) = ∑ uv∈E(G) [deg(u) + deg(v)] (or equivalently ∑ u∈V (G) [deg(u)2] and M2(G) = ∑ uv∈E(G) [deg(u)deg(v)] respectively. In this paper, we have obtained the first and second zagreb indices of the generalized complementary prisms Gm+n,Gm,n,G m,m and Gm,m. MSC: 05C15, 05C38.

The first and second Zagreb indices of some graph operations