OFFSET
0,17
LINKS
EXAMPLE
a(0)=0 because even though the null graph (on zero vertices) is vacuously 6-regular and connected, since it is acyclic, it has infinite girth.
The a(12)=1 graph is the complete bipartite graph K_{6,6}.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Jason Kimberley, Feb 28 2011
STATUS
approved