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Indexed by:Journal Papers

Date of Publication:2015-11-01

Journal:GRAPHS AND COMBINATORICS

Included Journals:SCIE、Scopus

Volume:31

Issue:6

Page Number:2275-2292

ISSN No.: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 .