

A058348


Number of connected 4regular simple graphs on n vertices with girth at least 6.


14



1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 4, 0, 19, 0, 1272, 25, 494031, 13504
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OFFSET

0,31


COMMENTS

The null graph on 0 vertices is vacuously connected and 4regular; since it is acyclic, it has infinite girth.
Does a(2n+1) ever exceed a(2n)?
(End)


LINKS



CROSSREFS

Connected kregular simple graphs with girth at least 6: A186726 (any k), A186716 (triangle); specified degree k: A185116 (k=2), A014374 (k=3), this sequence (k=4).
Connected 4regular simple graphs with girth at least g: A006820 (g=3), A033886 (g=4), A058343 (g=5), this sequence (g=6).
Connected 4regular simple graphs with girth exactly g: A184943 (g=3), A184944 (g=4), A184945 (g=5). (End)


KEYWORD

nonn,more,hard


AUTHOR



EXTENSIONS

Jason Kimberley inserted Meringer's computed terms a(n)=0 for n in [27,29,31,33] and appended terms a(35) and a(36), by running Meringer's GENREG for 17 and 106 processor days at U. Ncle, on May 04 2010.
a(37) appended from running GENREG for 450 processor days at U. Ncle. by Jason Kimberley, Dec 03 2011


STATUS

approved



