A104592 Number of labeled non-planar projective-planar 2-connected graphs without a K_{3,3}-subdivision and with n vertices.

1, 120, 10920, 988960, 99706320, 11897978400, 1729153068720, 306003079514880, 64657337524631280, 15890834362452489440, 4435396700216405763840, 1379778057502074926142720, 471689356958791639787042560

Offset

5,2

Comments

By empirical evidence, the terms possess a curious prime factor behavior. E.g. 2^7*3^2*5*11*17*19 divides a(19)=70291642269058321415718042668160.

Links

A. Gagarin et al., Table of n, a(n) for n = 5..20

A. Gagarin, G. Labelle and P. Leroux, Counting labeled projective-planar graphs without a K_{3,3}-subdivision, arXiv:math/0406140 [math.CO], 2004-2006.

Crossrefs

Cf. A104593, A135340.

Sequence in context: A221620 A299954 A226804 * A135379 A296913 A059063

Adjacent sequences: A104589 A104590 A104591 * A104593 A104594 A104595

Keyword

nonn

Author

Valery A. Liskovets, Mar 22 2005

Status

approved