A322930 a(n) is the number of rooted 6-regular maps with n vertices on the projective plane.
22, 864, 40512, 2075860, 112225776, 6289396632, 361699896960, 21210328632420, 1262859239910000, 76114899842912520
Offset: 1
Links
- E. Krasko, A. Omelchenko, Enumeration of r-regular Maps on the Torus. Part I: Enumeration of Rooted and Sensed Maps, arXiv:1709.03225 [math.CO], 2017.
- E. Krasko, A. Omelchenko, Enumeration of r-regular maps on the torus. Part I: Rooted maps on the torus, the projective plane and the Klein bottle. Sensed maps on the torus, Discrete Mathematics, Volume 342, Issue 2, February 2019, Pages 584-599.