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Related papers: Multiplicative Zagreb indices of cacti

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For a (molecular) graph, the first multiplicative Zagreb index $\prod_1(G) $ is the product of the square of every vertex degree, and the second multiplicative Zagreb index $\prod_2(G) $ is the product of the products of degrees of pairs of…

Combinatorics · Mathematics 2017-04-25 Shaohui Wang

For a graph $G$, the first multiplicative Zagreb index $\prod_1(G) $ is the product of squares of vertex degrees, and the second multiplicative Zagreb index $\prod_2(G) $ is the product of products of degrees of pairs of adjacent vertices.…

Combinatorics · Mathematics 2021-08-09 Shengjin Ji , Shaohui Wang , Tilahun Muche , Sakander Hayat

The first multiplicative Zagreb index of a graph $G$ is the product of the square of every vertex degree, while the second multiplicative Zagreb index is the product of the products of degrees of pairs of adjacent vertices. In this paper,…

Combinatorics · Mathematics 2017-04-21 Shaohui Wang , Chunxiang Wang , Lin Chen , Jia-Bao Liu

The edge Szeged index and edge-vertex Szeged index of a graph are defined as $Sz_{e}(G)=\sum\limits_{uv\in E(G)}m_{u}(uv|G)m_{v}(uv|G)$ and $Sz_{ev}(G)=\frac{1}{2} \sum\limits_{uv \in E(G)}[n_{u}(uv|G)m_{v}(uv|G)+n_{v}(uv|G)m_{u}(uv|G)],$…

Combinatorics · Mathematics 2017-11-08 Shengjie He , Rong-Xia Hao , Aimei Yu

For a graph $G$, the first multiplicative Zagreb index $\prod_1$ is equal to the product of squares of the vertex degrees, and the second multiplicative Zagreb index $\prod_2$ is equal to the product of the products of degrees of pairs of…

Combinatorics · Mathematics 2016-11-21 Shaohui Wang , Chunxiang Wang , Jia-Bao Liu

Let $G$ be a connected graph. The edge revised Szeged index of $G$ is defined as $Sz^{\ast}_{e}(G)=\sum\limits_{e=uv\in E(G)}(m_{u}(e|G)+\frac{m_{0}(e|G)}{2})(m_{v}(e|G)+\frac{m_{0}(e|G)}{2})$, where $m_{u}(e|G)$ (resp., $m_{v}(e|G)$) is…

Combinatorics · Mathematics 2018-04-18 Shengjie He , Rong-Xia Hao , Deming Li

The first Zagreb index of a graph $G$ is the sum of the square of every vertex degree, while the second Zagreb index is the sum of the product of vertex degrees of each edge over all edges. In our work, we solve an open question about…

Combinatorics · Mathematics 2017-09-07 Shengjin Ji , Shaohui Wang

The first Zagreb index $M_{1}$ of a graph is defined as the sum of the square of every vertex degree, and the second Zagreb index $M_{2}$ of a graph is defined as the sum of the product of vertex degrees of each pair of adjacent vertices.…

Combinatorics · Mathematics 2020-06-02 Xiaocong He , Xiaobo He

Let $\mathcal{C}_{n,k}$ be the family of all cacti with $k$ cycles and $n\geq4$ vertices. In the present note, the element of the class $\mathcal{C}_{n,k}$ having minimum augmented Zagreb index ($AZI$) is characterized. Moreover, some…

Combinatorics · Mathematics 2017-04-17 Akbar Ali , Akhlaq Ahmad Bhatti

A cactus is a connected graph in which each edge is contained in at most one cycle. We generalize the concept of cactus graphs, i.e., a $k$-cactus is a connected graph in which each edge is contained in at most $k$ cycles where $k\ge 1$. It…

Combinatorics · Mathematics 2023-09-12 Licheng Zhang , Yuanqiu Huang

The edge-Wiener index $W_e(G)$ of a connected graph $G$ is the sum of distances between all pairs of edges of $G$. A connected graph $G$ is said to be a cactus if each of its blocks is either a cycle or an edge. Let $\mathcal{G}_{n,t}$…

Combinatorics · Mathematics 2018-09-06 Siyan Liu , Rong-Xia Hao

For a simple graph $G$ with $n$ vertices and $m$ edges, the first Zagreb index and the second Zagreb index are defined as $M_1(G)=\sum_{v\in V}d(v)^2 $ and $M_2(G)=\sum_{uv\in E}d(u)d(v)$. In \cite{VGFAD}, it was shown that if a connected…

Discrete Mathematics · Computer Science 2015-03-19 Hosam Abdo , Darko Dimitrov , Ivan Gutman

The vertex PI index $PI(G) = \sum_{xy \in E(G)} [n_{xy}(x) + n_{xy}(y)]$ is a distance-based molecular structure descriptor, where $n_{xy}(x)$ denotes the number of vertices which are closer to the vertex $x$ than to the vertex $y$ and…

Combinatorics · Mathematics 2016-03-02 Chunxiang Wang , Shaohui Wang , Bing Wei

The subpath number of a graph G is defined as the total number of subpaths in G, and it is closely related to the number of subtrees, a well-studied topic in graph theory. This paper is a continuation of our previous paper [5], where we…

Combinatorics · Mathematics 2025-03-05 Martin Knor , Jelena Sedlar , Riste Škrekovski , Yu Yang

The Zagreb index of a hypergraph is defined as the sum of the squares of the degrees of its vertices. A connected $k$-uniform hypergraph with $n$ vertices and $m$ edges is called bicyclic if $n=m(k-1)-1$. In this paper, we determine the…

Combinatorics · Mathematics 2025-06-11 Hong Zhou , Changjiang Bu

The concept of resistance distance was first proposed by Klein and Randi\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each…

Combinatorics · Mathematics 2015-11-11 Wen-Rui Wang , Xiang-Feng Pan

For a molecular graph, the first multiplicative Zagreb index $\Pi_1$ is equal to the product of the square of the degree of the vertices, while the second multiplicative Zagreb index $\Pi_2$ is equal to the product of the endvertex degree…

Combinatorics · Mathematics 2017-05-09 Shaohui Wang , Chunxiang Wang , Lin Chen

The first multiplicative Zagreb index of a graph $G$ is the product of the square of every vertex degree, while the second multiplicative Zagreb index is the product of the degree of each edge over all edges. In our work, we explore the…

Combinatorics · Mathematics 2017-04-28 Chunxiang Wang , Jia-Bao Liu , Shaohui Wang

We show that on cactus graphs the Szeged index is bounded above by twice the Wiener index. For the revised Szeged index the situation is reversed if the graph class is further restricted. Namely, if all blocks of a cactus graph are cycles,…

Combinatorics · Mathematics 2022-11-15 Stefan Hammer

Let G be a simple connected molecular graph with vertex set $V(G)$ and edge set $E(G)$. One important modification of classical Zagreb index, called hyper Zagreb index $HM(G)$ is defined as the sum of squares of the degree sum of the…

Discrete Mathematics · Computer Science 2017-03-27 Nilanjan De
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