Release Time:2019-03-09  Hits:

Indexed by: Journal Papers

Date of Publication: 2015-11-01

Journal: GRAPHS AND COMBINATORICS

Included Journals: Scopus、SCIE

Volume: 31

Issue: 6

Page Number: 2275-2292

ISSN: 0911-0119

Key Words: [r, s, t]-coloring; [r, s, t]-chromatic number; Friendship graphs; Wheels

Abstract: Given non-negative integers and , an -coloring of a graph is a mapping from to the color set such that for every two adjacent vertices , , for every two adjacent edges , , and for every vertex and an incident edge , respectively. The minimum such that admits an -coloring is called the -chromatic number of and is denoted by . In this paper, we examine exact values and upper bounds for the -chromatic number of friendship graphs and wheels for every positive integer and .