

A318188


Number of nonisomorphic 2connected circle graphs of order n.


0




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], 20082009.
L. E. Danielsen and M. G. Parker, Interlace polynomials: Enumeration, unimodality, and connections to codes, Discrete Appl. Math. 158(6), pp. 636648, 2010.


EXAMPLE

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


CROSSREFS

Cf. A156809, A156808, A002218.
Sequence in context: A071895 A054422 A074503 * A301920 A229311 A208480
Adjacent sequences: A318185 A318186 A318187 * A318189 A318190 A318191


KEYWORD

nonn,hard,more


AUTHOR

Fidel I. Schaposnik, Sep 01 2018


STATUS

approved



