OFFSET
1,1
LINKS
R. de Mello Koch, S. Ramgoolam, Strings from Feynman graph counting: Without large N, Phys. Rev. D 85 (2012) 026007. Different from a(7) onwards.
R. Coquereaux, J.-B. Zuber, Maps, immersions and permutations, arXiv preprint arXiv:1507.03163, 2015. Also J. Knot Theory Ramifications 25, 1650047 (2016),
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Mar 02 2016
EXTENSIONS
a(11) and beyond from Euler transform of A170946 - R. J. Mathar, Apr 07 2022
STATUS
approved