Geodesic growth in right-angled and even Coxeter groups

The objective of this paper is to detect which combinatorial properties of a regular graph can completely determine the geodesic growth of the right-angled Coxeter or Artin group this graph defines, and to provide the first examples of right-angled and even Coxeter groups with the same geodesic growth series.
Comment: 27 pages, 5 figures. Some typos and minor errors were corrected