A164099 Number of planar graphs with n nodes and chromatic number 2.

1, 2, 6, 12, 33, 83, 273, 937, 3983, 18871, 103697, 628245, 4161652, 29372754, 218035754

Offset

2,2

Links

Table of n, a(n) for n=2..16.

Formula

(Euler transform of A243321) - 1. - Falk Hüffner, May 10 2019

Crossrefs

Sequence in context: A217447 A057579 A096610 * A088808 A076278 A221989

Adjacent sequences: A164096 A164097 A164098 * A164100 A164101 A164102

Keyword

nonn

Author

Keith Briggs, Aug 10 2009

Extensions

Added term 18871 (for n=11), Keith Briggs, Aug 25 2009

a(12)-a(16) from formula by Falk Hüffner, May 10 2019

Status

approved