A207408 Number of connected triangle-free graphs on n nodes with edge chromatic number 3.

0, 0, 0, 1, 4, 12, 27, 84, 212, 694, 2105, 7354, 25469, 95631, 364957

Offset

1,5

Links

Table of n, a(n) for n=1..15.

Crossrefs

Cf. A116079, A207410, A207411, A207412.

Sequence in context: A013697 A306055 A212522 * A366998 A064444 A072182

Adjacent sequences: A207405 A207406 A207407 * A207409 A207410 A207411

Keyword

nonn,more

Author

Michael Sollami, Feb 17 2012

Status

approved