A268571 Number of immersions of unoriented circle into unoriented sphere with n double points and no simple loop.

0, 0, 1, 1, 2, 5, 16, 52, 205, 863

Offset: 1

Author

N. J. A. Sloane, Mar 03 2016

Keywords

• nonn
• more

Links

• Robert Coquereaux and Jean-Bernard Zuber, Maps, immersions and permutations, Journal of Knot Theory and Its Ramifications, Vol. 25, No. 8 (2016), 1650047; arXiv preprint, arXiv:1507.03163 [math.CO], 2015-2016. See Table 6.
• Guy Valette, A Classification of Spherical Curves Based on Gauss Diagrams, Arnold Math. J. (2016) 2:383-405. See Table 7.

Crossrefs

Cf. A008989, A264759, A268568, A268569, A268570, A268572.

Extensions

Name clarified by Andrey Zabolotskiy, Jun 09 2024