A008984 Number of immersions of the oriented circle into the oriented plane with n double points and index n-1.

1, 1, 3, 10, 35, 133, 538, 2144, 8643, 34690, 139122, 556618

Offset

0,3

References

V. I. Arnold, Topological Invariants of Plane Curves and Caustics, American Math. Soc., 1994, p. 18.

Links

Table of n, a(n) for n=0..11.

Crossrefs

Cf. A008980, A008981, A008982, A008983, A008985, A054993.

Sequence in context: A221130 A084781 A151047 * A151048 A149038 A097148

Adjacent sequences: A008981 A008982 A008983 * A008985 A008986 A008987

Keyword

nonn,nice,more,changed

Author

N. J. A. Sloane

Extensions

Name corrected by Andrey Zabolotskiy, Oct 22 2023

a(6)-a(11) from Andrey Zabolotskiy, Jan 19 2025

Status

approved