A268561 Arises in counting maps on a surface: see Coquereaux-Zuber (2015) for precise definition.

2, 3, 12, 37, 198, 1143, 7658, 54559, 413086, 3251240

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: A353831 A107240 A099171 * A352099 A012307 A012311

Adjacent sequences: A268558 A268559 A268560 * A268562 A268563 A268564

Keyword

nonn,more

Author

N. J. A. Sloane, Mar 02 2016

Status

approved