Editing Chromatic polynomial (section)

===Efficient algorithms===
For some basic graph classes, closed formulas for the chromatic polynomial are known. For instance this is true for trees and cliques, as listed in the table above.

Polynomial time algorithms are known for computing the chromatic polynomial for wider classes of graphs, including [[chordal graph]]s<ref>{{harvtxt|Naor|Naor|Schaffer|1987}}.</ref> and graphs of bounded [[clique-width]].<ref>{{harvtxt|Giménez|Hliněný|Noy|2005}}; {{harvtxt|Makowsky|Rotics|Averbouch|Godlin|2006}}.</ref> The latter class includes [[cograph]]s and graphs of bounded [[tree-width]], such as [[outerplanar graph]]s.