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A063550 Largest number of crossing-free matchings on a set S of n points in the plane, that is, a set of floor(n/2) pairwise non-intersecting segments with endpoints in S having no endpoint in common. 1
1, 1, 3, 3, 14, 12, 79, 56, 497, 311 (list; graph; refs; listen; history; text; internal format)
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.
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
Cf. A063549.
Sequence in context: A287501 A287537 A186373 * A367672 A298960 A356117
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

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Last modified April 18 21:51 EDT 2024. Contains 371781 sequences. (Running on oeis4.)