A234278 The number of circular maps C(n) with n edges regardless of genus.

1, 2, 5, 16, 56, 333, 2147, 17456, 158022, 1604281, 17863089, 216774585, 2844162968, 40129498111, 605894465441, 9748493596584, 166520626541070, 3009885559478844, 57397289146583917, 1151666341035710396

Offset

1,2

Comments

The circular maps are also the maps whose faces could be colored in two colors.

Links

Table of n, a(n) for n=1..20.

M. A. Deryagina and A. D. Mednykh, On the enumeration of circular maps with given number of edges, Siberian Mathematical Journal, 54, No. 6, 2013, 624-639.

M. Deryagina, On the enumeration of hypermaps which are self-equivalent with respect to reversing the colors of vertices, Preprint 2016.

Formula

See formula for C(n) in Theorem 2.1 of Deryagina and Mednykh (2013).

Crossrefs

Sequence in context: A195931 A350906 A082789 * A180678 A072110 A323229

Adjacent sequences: A234275 A234276 A234277 * A234279 A234280 A234281

Keyword

nonn

Author

N. J. A. Sloane, Dec 28 2013, based on email from Madina Deryagina and Alexander Mednykh.

Status

approved