A268556 Arises in counting maps on a surface: see Coquereaux-Zuber (2015) for precise definition.

2, 10, 54, 491, 6430, 119475, 2775582, 76733201, 2439149685

Offset

1,1

Links

Table of n, a(n) for n=1..9.

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: A365879 A202365 A330620 * A371816 A175935 A216721

Adjacent sequences: A268553 A268554 A268555 * A268557 A268558 A268559

Keyword

nonn,more

Author

N. J. A. Sloane, Mar 02 2016

Status

approved