OFFSET
0,3
COMMENTS
Needs a more precise definition.
LINKS
R. J. Mathar, Topologically Distinct Sets of Non-intersecting Circles in the Plane, arXiv:1603.00077 [math.CO], 2016. See (102).
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 20 2017
STATUS
approved