Y. Sun

collaborators

3 papers

math.CO2021

Refined Eulerian numbers and ballot permutations

Tongyuan Zhao, Yue Sun, Feng Zhao

A ballot permutation is a permutation π such that in any prefix of π the descent number is not more than the ascent number. In this article, we obtained a formula in close form for…

math.CO2016

Asymptotics of Ramsey numbers of double stars

Sergey Norin, Yue Ru Sun, Yi Zhao

A double star $S (n, m)$ is the graph obtained by joining the center of a star with $n$ leaves to a center of a star with $m$ leaves by an edge. Let $r (S (n, m))$ denote the Ramsey num…

math.CO2016

Triangle-independent sets vs. cuts

Sergey Norin, Yue Ru Sun

A set of edges $T$ in a graph $G$ is triangle-independent if $T$ contains at most one edge from each triangle in $G$ . Let $α_{1} (G)$ denote the maximum size of the triangle-independe…