OFFSET
0,11
LINKS
CROSSREFS
Not necessarily connected k-regular simple graphs girth exactly 4: A198314 (any k), A185644 (triangle); fixed k: A026797 (k=2), A185134 (k=3), this sequence (k=4).
KEYWORD
nonn,hard,more
AUTHOR
Jason Kimberley, Nov 04 2011
EXTENSIONS
Corrected by Jason Kimberley, Jan 03 2013
STATUS
approved