SHANDONG SCIENCE ›› 2017, Vol. 30 ›› Issue (3): 94-97.doi: 10.3976/j.issn.1002-4026.2017.03.016

• Other Research Article • Previous Articles     Next Articles

A conjecture about coloring of non-planar graphs

ZHANG Xiang-bo   

  1. Linpan Middle School,Dezhou 251507,China
  • Received:2016-04-27 Online:2017-06-20 Published:2017-06-20

Abstract:

The following conjecture was proposed in this paper: If θ(G)=2, then   χ(G)≤9; If θ(G)≥3, then   χ(G)≤6θ(G)-1.The conjecture is proved to be true forS∈p,p-1,p-2,p-3,p-4,p-5.

Key words: four-color problem, thickness of a graph, planar graphs, vertex coloring number

CLC Number: 

  • O157.5