A268560 Arises in counting maps on a surface: see Coquereaux-Zuber (2015) for precise definition.

2, 16, 336, 12480, 689664, 51440640, 4870932480, 561752432640, 76597275525120, 12077498082263040

Offset

1,1

Links

Table of n, a(n) for n=1..10.

R. Coquereaux, J.-B. Zuber, Maps, immersions and permutations, arXiv preprint arXiv:1507.03163, 2015. Also J. Knot Theory Ramifications 25, 1650047 (2016), DOI: http://dx.doi.org/10.1142/S0218216516500474

Crossrefs

Sequence in context: A294039 A009100 A009109 * A275854 A299907 A012610

Adjacent sequences: A268557 A268558 A268559 * A268561 A268562 A268563

Keyword

nonn,more

Author

N. J. A. Sloane, Mar 02 2016

Status

approved