We present a deterministic algorithm producing the number of
 $k$-colourings of a graph on $n$ vertices in time
 $2^nn^{O(1)}$.
 We also show that the chromatic number can be found by a 
 polynomial space algorithm running in time $O(2.2461^n)$.
 Finally, we present a family of ...
                	
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 We present a randomized algorithm that takes as input an undirected $n$-vertex graph $G$ with maximum degree $\Delta$ and an integer $k > 3\Delta$, and returns a random proper $k$-coloring of $G$. The 
 distribution of the coloring is perfectly uniform over the set of all proper $k$-colorings; ...
                	
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