Needs more terms and a b-file (note that one of the links gives the first 100 terms).
Table of n, a(n) for n=2..12.
Marston Conder, Home Page (Contains tables of regular maps, hypermaps and polytopes, trivalent symmetric graphs, and surface actions)
Marston Conder, Orientable proper regular hypermaps of genus 2 to 101
Sequence in context: A037007 A066025 A009824 * A314273 A087090 A161756
Adjacent sequences: A286273 A286274 A286275 * A286277 A286278 A286279
N. J. A. Sloane, May 08 2017