A318188 Number of nonisomorphic 2-connected circle graphs of order n.

0, 1, 1, 3, 10, 54, 407, 4630, 68425, 1211637

Offset

1,4

Links

Table of n, a(n) for n=1..10.

L. E. Danielsen, Database of Circle Graphs

L. E. Danielsen and M. G. Parker, Interlace polynomials: Enumeration, unimodality, and connections to codes, arXiv:0804.2576 [math.CO], 2008-2009.

L. E. Danielsen and M. G. Parker, Interlace polynomials: Enumeration, unimodality, and connections to codes, Discrete Appl. Math. 158(6), pp. 636-648, 2010.

Example

The 3 circle graphs with n = 4 vertices which are 2-connected are K_4, the square and the square with one diagonal.

Crossrefs

Cf. A156809, A156808, A002218.

Sequence in context: A390214 A054422 A074503 * A229311 A208480 A342966

Adjacent sequences: A318185 A318186 A318187 * A318189 A318190 A318191

Keyword

nonn,hard,more

Author

Fidel I. Schaposnik, Sep 01 2018

Status

approved