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A172144 Number of chirotopes resulting from realizable uniform oriented matroids of rank 3 over a ground set of n elements modulo permutations. 1
1, 3, 4, 41, 706, 28287 (list; graph; refs; listen; history; text; internal format)
OFFSET
3,2
COMMENTS
The above numbers were obtained from random sprinkling of points into S^2.
The first five entries match those constructed from A018242, by explicitly applying each reorientation to a representative chirotope for each class of A018242, and grouping the chirotopes related by a permutation.
REFERENCES
J. Brunnemann and D. Rideout, "Oriented matroids—combinatorial structures underlying loop quantum gravity", Class.Quant.Grav. 27, 205008 (2010).
J. Richter-Gebert, "On the Realizability Problem of Combinatorial Geometries - Decision Methods", Ph.D. thesis, TH-Darmstadt 1992, 144 pages.
LINKS
CROSSREFS
Cf. A018242.
Sequence in context: A012876 A300882 A348225 * A032837 A127614 A041055
KEYWORD
nonn,more
AUTHOR
Johannes Brunnemann (jbrunnem(AT)math.upb.de) and David Rideout, Nov 19 2010
STATUS
approved

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Last modified April 15 04:52 EDT 2024. Contains 371667 sequences. (Running on oeis4.)