A021103 Number of two-connected (or biconnected) planar graphs with n nodes.

0, 0, 0, 1, 3, 9, 44, 294, 2893, 36496, 545808, 9029737, 159563559, 2952794985, 56589742050

Offset

0,5

Comments

For n < 3, conventions vary: Read & Wilson set a(2) = 0, but Gagarin et al. set a(2) = 1. - Andrey Zabolotskiy, Jun 07 2023

References

R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998. See p. 229.

Links

Table of n, a(n) for n=0..14.

A. Gagarin, G. Labelle, P. Leroux, and T. Walsh, Structure and enumeration of two-connected graphs with prescribed three-connected components, Adv. in Appl. Math. 43 (2009), no. 1, pp. 46-74. See (116) on p. 69.

Crossrefs

Row sums of A049336.

The labeled version is A096331.

Cf. A000944 (3-connected), A002218, A003094, A005470.

Sequence in context: A262128 A028858 A058106 * A222662 A209977 A001902

Adjacent sequences: A021100 A021101 A021102 * A021104 A021105 A021106

Keyword

nonn,more

Author

Brendan McKay

Extensions

a(12)-a(14) from Gilbert Labelle (labelle.gilbert(AT)uqam.ca), Jan 20 2009

Offset 0 from Michel Marcus, Jun 05 2023

a(2) changed back to 0 by Georg Grasegger and Andrey Zabolotskiy, Jun 07 2023

Status

approved