Yongxin Lan

activity

20172026

most citedPlanar anti-Ramsey numbers for paths and cycles

5 citations · 19 across the 14 of their papers we have counts for

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15 papers · 1 filter

math.CO2026

Improved Bounds for Unavoidable Claws in Tournaments

Jiangdong Ai, Yongxin Lan

Let $u (n)$ be the largest integer $d$ such that every $n$ -vertex claw with at most $d$ branches occurs in every tournament on $n$ vertices, and let $c_{\mathrm{claw}}=\limsup_{n\to…

math.CO2026

The planar Turán number of ${K_{4}, Θ_{6}^{i}}$

Jing Chen, Kai Gao, Yongxin Lan +2

Let $H$ be a family of graphs. A graph is said to be $H$ -free if it contains no subgraph isomorphic to a graph in $H$ . The planar Turán number $ex_{_\…

math.CO2026

The Outerplanar Turán Number of Double Stars

Chaofan Zhang, Yongxin Lan, Changqing Xu

Let $H$ be a nonempty graph. A graph is $H$ -free if it does not contain any copy of $H$ as a subgraph. The outerplanar Turán number of $H$ , denoted by $e x_{_{O P}} (n, H)$ , is…

math.CO2022★ 2 cited

An improved lower bound for the planar Turán number of cycles

Yongxin Lan, Zi-Xia Song

The planar Turán number of a graph $H$ , denoted by $e x_{_{P}} (n, H)$ , is the largest number of edges in a planar graph on $n$ vertices without containing $H$ as a subgraph.…

math.CO2022

Planar Turán numbers of cubic graphs and disjoint union of cycles

Yongxin Lan, Yongtang Shi, Zi-Xia Song

The planar Turán number of a graph $H$ , denoted $e x_{_{P}} (n, H)$ , is the maximum number of edges in a planar graph on $n$ vertices without containing $H$ as a subgraph. Thi…

math.CO2021

The saturation number of $C_{6}$

Yongxin Lan, Yongtang Shi, Yiqiao Wang +1

A graph $G$ is called $C_{k}$ -saturated if $G$ is $C_{k}$ -free but $G + e$ not for any $e \in E (G)$ . The saturation number of $C_{k}$ , denoted $s a t (n, C_{k})$ , is the minimum number…

math.CO2020

Improved bounds for anti-Ramsey numbers of matchings in outerplanar graphs

Yifan Pei, Yongxin Lan, Hua He

Let $O_{n}$ be the set of all maximal outerplanar graphs of order $n$ . Let $a r (O_{n}, F)$ denote the maximum positive integer $k$ such that $T \in O_{n}$ has…

math.CO2019★ 3 cited

Exact rainbow numbers for matchings in plane triangulations

Zhongmei Qin, Yongxin Lan, Yongtang Shi +1

Given two graphs $G$ and $H$ , the {\it rainbow number} $r b (G, H)$ for $H$ with respect to $G$ is defined as the minimum number $k$ such that any $k$ -edge-coloring of $G$ contains a…

math.CO2018★ 3 cited

Extremal $H$ -free planar graphs

Yongxin Lan, Yongtang Shi, Zi-Xia Song

Given a graph $H$ , a graph is $H$ -free if it does not contain $H$ as a subgraph. We continue to study the topic of "extremal" planar graphs, that is, how many edges can an $H$ -free…

math.CO2018★ 1 cited

Planar anti-Ramsey numbers of matchings

Gang Chen, Yongxin Lan, Zi-Xia Song

Given a positive integer $n$ and a planar graph $H$ , let $T_{n} (H)$ be the family of all plane triangulations $T$ on $n$ vertices such that $T$ contains a subgraph isomorph…

math.CO2018★ 1 cited

Improved bounds for rainbow numbers of matchings in plane triangulations

Zhongmei Qin, Yongxin Lan, Yongtang Shi

Given two graphs $G$ and $H$ , the {\it rainbow number} $r b (G, H)$ for $H$ with respect to $G$ is defined as the minimum number $k$ such that any $k$ -edge-coloring of $G$ contains a…

math.CO2018

Degree powers in graphs with a forbidden forest

Yongxin Lan, Henry Liu, Zhongmei Qin +1

Given a positive integer $p$ and a graph $G$ with degree sequence $d_{1}, \dots, d_{n}$ , we define $e_{p} (G) = \sum_{i = 1}^{n} d_{i}^{p}$ . Caro and Yuster introduced a Turán-type problem for $e_p(G…

math.CO2017

The Turan number of 2P_7

Yongxin Lan, Zhongmei Qin, Yongtang Shi

The Turán number of a graph $H$ , denoted by $e x (n, H)$ , is the maximum number of edges in any graph on $n$ vertices which does not contain $H$ as a subgraph. Let $P_{k}$ denote the…

math.CO2017★ 4 cited

Extremal Theta-free planar graphs

Yongxin Lan, Yongtang Shi, Zi-Xia Song

Given a family $F$ , a graph is $F$ -free if it does not contain any graph in $F$ as a subgraph. We study the topic of "extremal" planar graphs initiate…

math.CO2017★ 5 cited

Planar anti-Ramsey numbers for paths and cycles

Yongxin Lan, Yongtang Shi, Zi-Xia Song

Motivated by anti-Ramsey numbers introduced by Erdős, Simonovits and Sós in 1975, we study the anti-Ramsey problem when host graphs are plane triangulations. Given a positive integ…

Improved Bounds for Unavoidable Claws in Tournaments

The planar Turán number of {K4​,Θ6i​}

The Outerplanar Turán Number of Double Stars

An improved lower bound for the planar Turán number of cycles

Planar Turán numbers of cubic graphs and disjoint union of cycles

The saturation number of C6​

Improved bounds for anti-Ramsey numbers of matchings in outerplanar graphs

Exact rainbow numbers for matchings in plane triangulations

Extremal H-free planar graphs

Planar anti-Ramsey numbers of matchings

Improved bounds for rainbow numbers of matchings in plane triangulations

Degree powers in graphs with a forbidden forest

The Turan number of 2P_7

Extremal Theta-free planar graphs

Planar anti-Ramsey numbers for paths and cycles

The planar Turán number of ${K_{4}, Θ_{6}^{i}}$

The saturation number of $C_{6}$

Extremal $H$ -free planar graphs