OFFSET
1,3
LINKS
O. Aichholzer and H. Krasser, The point set order type data base: a collection of applications and results, pp. 17-20 in Abstracts 13th Canadian Conference on Computational Geometry (CCCG '01), Waterloo, Aug. 13-15, 2001.
M. Sharir and E. Welzl. On the Number of Crossing-Free Matchings, (Cycles, and Partitions)
EXAMPLE
The Sharir link contains an image (Figure 1) of a placement of 6 points in the plane such that 12 of their perfect matchings are crossing-free, demonstrating that a(6) >= 12. - Nathaniel Johnston, Nov 17 2014
CROSSREFS
KEYWORD
nonn,nice,hard,more
AUTHOR
N. J. A. Sloane, Aug 14 2001
EXTENSIONS
a(1) = a(2) = 1 inserted by Nathaniel Johnston, Nov 17 2014
Name clarified by Manfred Scheucher, Mar 12 2018
STATUS
approved