A076318 Number of 6-colorable (i.e., chromatic number <= 6) simple graphs on n nodes.

1, 2, 4, 11, 34, 156, 1043, 12338, 274541, 12000742, 1018595454

Offset

1,2

Links

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

Eric Weisstein's World of Mathematics, n-Colorable Graph

Formula

a(n) = A076317(n) + A076282(n). - Andrew Howroyd, Dec 02 2018

Crossrefs

Cf. A033995, A076282, A076315, A076316, A076317, A076319, A076320, A076321.

Sequence in context: A156809 A215620 A076317 * A046750 A076319 A178944

Adjacent sequences: A076315 A076316 A076317 * A076319 A076320 A076321

Keyword

nonn,more

Author

Eric W. Weisstein, Oct 06 2002

Extensions

a(10)-a(11) from Andrew Howroyd, Dec 02 2018

Status

approved