A113202 Number of isomorphism classes of simple quadrangulations of the sphere having n vertices and n-2 faces, with orientation-reversing isomorphisms forbidden.

1, 1, 2, 3, 10, 21, 83, 298, 1339, 6049, 29765, 148842, 770267, 4054539, 21743705, 118237471, 651370528, 3628421181, 20416662314, 115919209155, 663548898942, 3826577783917, 22217382001865, 129800215435088

Offset

4,3

Links

Table of n, a(n) for n=4..27.

G. Brinkmann, S. Greenberg, C. Greenhill, B. D. McKay, R. Thomas, and P. Wollan, Generation of simple quadrangulations of the sphere, Discr. Math., 305 (2005), 33-54.

Gunnar Brinkmann and Brendan McKay, plantri and fullgen programs for generation of certain types of planar graph.

Gunnar Brinkmann and Brendan McKay, plantri and fullgen programs for generation of certain types of planar graph [Cached copy, pdf file only, no active links, with permission]

CombOS - Combinatorial Object Server, generate planar graphs

Crossrefs

Cf. A113201, A078666, A007022, A002880, A113203, A113204, A113205.

Sequence in context: A064497 A161522 A120484 * A079078 A285794 A148056

Adjacent sequences: A113199 A113200 A113201 * A113203 A113204 A113205

Keyword

nonn

Author

N. J. A. Sloane, Jan 07 2006

Status

approved