A215620 Numbers of apex graphs (graphs which become or remain planar upon the removal of a single vertex) on n vertices.

1, 2, 4, 11, 34, 155, 1026, 11666, 226916, 6810525

Offset

1,2

Comments

Trivially includes planar graphs.

Links

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

Eric Weisstein's World of Mathematics, Apex Graph

Crossrefs

Cf. A215621 (nonplanar apex graphs).

Cf. A076317 (number of 5-colorable simple graphs on n nodes).

Sequence in context: A217043 A249696 A156809 * A076317 A076318 A046750

Adjacent sequences: A215617 A215618 A215619 * A215621 A215622 A215623

Keyword

nonn,more

Author

Eric W. Weisstein, Aug 17 2012

Extensions

a(10) from Eric W. Weisstein, Aug 20 2012

Status

approved