Chromatic Number in Time O(2.4023^n) Using Maximal Independent Sets

Abstract

In this paper we improve an algorithm by Eppstein (2001) for finding the chromatic number of a graph. We modify the algorithm slightly, and by using a bound on the number of maximal independent sets of size  k from our recent paper (2003), we prove that the running time is O(2.4023^n). Eppstein's algorithm runs in time O(2.4150^n). The space usage for both algorithms is O(2^n).