

A185336


Number of not necessarily connected 3regular simple graphs on 2n vertices with girth at least 6.


4



1, 0, 0, 0, 0, 0, 0, 1, 1, 5, 32, 385, 7574, 181227, 4624502, 122090545, 3328929960, 93990692632
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,10


COMMENTS

The null graph on 0 vertices is vacuously 3regular; since it is acyclic, it has infinite girth.


LINKS

Table of n, a(n) for n=0..17.
Jason Kimberley, Index of sequences counting not necessarily connected kregular simple graphs with girth at least g


FORMULA

Euler transformation of A014374.


CROSSREFS

3regular simple graphs with girth at least 6: A014374 (connected), A185236 (disconnected), this sequence (not necessarily connected).
Not necessarily connected kregular simple graphs with girth at least 6: A185326 (k=2), this sequence (k=3).
Not necessarily connected 3regular simple graphs with girth *at least* g: A005638 (g=3), A185334 (g=4), A185335 (g=5), this sequence (g=6).
Not necessarily connected 3regular simple graphs with girth *exactly* g: A185133 (g=3), A185134 (g=4), A185135 (g=5), A185136 (g=6).
Sequence in context: A006926 A185136 A014374 * A125709 A203112 A174471
Adjacent sequences: A185333 A185334 A185335 * A185337 A185338 A185339


KEYWORD

nonn,more,hard


AUTHOR

Jason Kimberley, Jan 28 2012


STATUS

approved



