The (3,18)-Graph of Order 2560

Our (3,18)-graph has 2560 vertices. It is a lift of the multigraph in the figure on the right. Compare this graph to the base graph used in our (3,14)-graph. The automorphism group of the graph has order 640.

The lifting group has order 320, and is SmallGroup(320,696) in the GAP Library of small groups. Some miscellaneous facts about the group:

  • The group is nonabelian.
  • It has 44 conjugacy classes.
  • It is solvable, supersolvable, but not nilpotent.
  • If two elements are randomly chosen from this group, the probability that they commute is 43/319.
  • The maximum order among group elements is 20.
  • The Sylow 2-subgroups are nonabelian with exponent 8.
  • The Sylow 5-subgroup is normal, so the full group is a semi-direct product.

Geoff Exoo