The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126729 Number of graphs on n nodes with edge chromatic number 3. 0
0, 0, 1, 5, 14, 46, 123, 375, 1061, 3331 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
Table of n, a(n) for n=1..10.
Keith M. Briggs, Combinatorial Graph Theory
CROSSREFS
A diagonal of triangle in A123962.
Sequence in context: A270636 A077335 A176640 * A336006 A098730 A244236
Adjacent sequences: A126726 A126727 A126728 * A126730 A126731 A126732
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 16 2007
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 6 04:28 EDT 2024. Contains 373115 sequences. (Running on oeis4.)