

A063851


Triangle T(n,k) (n >= 3, k = 1..n2) read by rows giving number of nonisomorphic nondegenerate oriented matroids with n points in nk dimensions.


5



1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 11, 11, 1, 1, 1, 135, 2628, 135, 1, 1, 1, 4382, 9276601, 9276601, 4382, 1, 1, 1, 312356
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OFFSET

3,10


REFERENCES

Lukas Finschi, A Graph Theoretical Approach for Reconstruction and Generation of Oriented Matroids, A dissertation submitted to the Swiss Federal Institute of Technology, Zurich for the degree of Doctor of Mathematics, 2001.
Fukuda, Komei; Miyata, Hiroyuki; Moriyama, Sonoko. Complete Enumeration of Small Realizable Oriented Matroids. Discrete Comput. Geom. 49 (2013), no. 2, 359381. MR3017917.  From N. J. A. Sloane, Feb 16 2013 [Beware typos in Table 1.]


LINKS

Table of n, a(n) for n=3..34.
L. Finschi, Homepage of Oriented Matroids
L. Finschi and K. Fukuda, Complete combinatorial generation of small point set configurations and hyperplane arrangements, pp. 97100 in Abstracts 13th Canadian Conference on Computational Geometry (CCCG '01), Waterloo, Aug. 1315, 2001.


EXAMPLE

Triangle begins:
1
1,1,
1,1,1,
1,1,1,4,
1,1,1,11,11,
1,1,1,135,2628,135,
1,1,1,4382,9276601,9276601,4382,
1,1,1,312356,...


CROSSREFS

For numbers when degenerate matroids are included see A063804. Rightmost diagonal gives A006248. Row sums give A063852.
Sequence in context: A113196 A037291 A222317 * A124777 A203639 A265679
Adjacent sequences: A063848 A063849 A063850 * A063852 A063853 A063854


KEYWORD

nonn,tabl,nice,more


AUTHOR

N. J. A. Sloane, Aug 26 2001


EXTENSIONS

More terms taken from Fukuda et al., 2013.  N. J. A. Sloane, Feb 16 2013


STATUS

approved



