cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

User: David Rideout

David Rideout's wiki page.

David Rideout has authored 2 sequences.

A172149 Number of chirotopes resulting from realizable uniform oriented matroids of rank 3 over a ground set of n elements.

Original entry on oeis.org

2, 16, 384, 23808, 3486720
Offset: 3

Views

Author

Johannes Brunnemann (jbrunnem(AT)math.upb.de) and David Rideout, Nov 19 2010

Keywords

Comments

The above numbers were obtained from random sprinkling of points into S^2.

References

  • J. Brunnemann and D. Rideout, "Oriented matroids—combinatorial structures underlying loop quantum gravity", Class.Quant.Grav. 27, 205008 (2010).
  • J. Brunnemann and D. Rideout, "Properties of the Volume Operator in Loop Quantum Gravity II: Detailed Presentation", Class.Quant.Grav. 25 065002 (2008).

Crossrefs

A172144

A172144 Number of chirotopes resulting from realizable uniform oriented matroids of rank 3 over a ground set of n elements modulo permutations.

Original entry on oeis.org

1, 3, 4, 41, 706, 28287
Offset: 3

Views

Author

Johannes Brunnemann (jbrunnem(AT)math.upb.de) and David Rideout, Nov 19 2010

Keywords

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.

Crossrefs

Cf. A018242.

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