login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A325628
Number of mirror-symmetric Euclidean pseudo-order types: nondegenerate abstract order types of configurations of n points in the plane with a mirroring automorphism.
2
0, 1, 1, 2, 3, 12, 28, 225, 825, 13103, 76188, 2358635, 21954947
OFFSET
1,4
LINKS
S. Felsner and J. E. Goodman, Pseudoline Arrangements. In: Toth, O'Rourke, Goodman (eds.) Handbook of Discrete and Computational Geometry, 3rd edn. CRC Press, 2018.
FORMULA
Asymptotics: a(n) = 2^(Theta(n^2)). This is Bachmann-Landau notation, that is, there are constants n_0, c, and d, such that for every n >= n_0 the inequality 2^{c n^2} <= a(n) <= 2^{d n^2} is satisfied. For more information see e.g. the Handbook of Discrete and Computational Geometry. - Manfred Scheucher, Sep 12 2019
CROSSREFS
Sequence in context: A249490 A075269 A215602 * A359221 A228501 A089414
KEYWORD
nonn,more
AUTHOR
STATUS
approved