A292971 Number of 4-regular maps with n vertices on the torus, up to orientation-preserving isomorphisms.

1, 4, 23, 185, 1647, 16455, 169734, 1805028, 19472757, 212603589, 2341275180, 25969695728, 289782412836, 3250137255678

Offset

1,2

Links

Table of n, a(n) for n=1..14.

E. Krasko, A. Omelchenko, Enumeration of r-regular Maps on the Torus. Part I: Enumeration of Rooted and Sensed Maps, arXiv preprint 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, pp. 584-599.

Crossrefs

Cf. A292408 (3-regular), A292972 (5-regular), A292974 (6-regular).

Sequence in context: A378090 A192840 A302189 * A317967 A186117 A108953

Adjacent sequences: A292968 A292969 A292970 * A292972 A292973 A292974

Keyword

nonn,more

Author

Evgeniy Krasko, Sep 27 2017

Status

approved