A126751 Number of biconnected graphs on n nodes with chromatic number 3.

0, 0, 1, 1, 6, 30, 232, 2762, 50814, 1420183, 58836784

Offset

1,5

Links

Table of n, a(n) for n=1..11.

Keith M. Briggs, Combinatorial Graph Theory

Crossrefs

A diagonal of triangle in A126749.

The sequence for "connected" is A126737.

Sequence in context: A208942 A209070 A259820 * A009689 A228873 A366809

Adjacent sequences: A126748 A126749 A126750 * A126752 A126753 A126754

Keyword

nonn,more

Author

N. J. A. Sloane, Feb 18 2007

Extensions

a(11) from Michael Sollami, Feb 18 2012

Status

approved