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.

0, 1, 1, 2, 3, 12, 28, 225, 825, 13103, 76188, 2358635, 21954947

Offset

1,4

Links

Table of n, a(n) for n=1..13.

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

Cf. A006247, A325595.

Sequence in context: A249490 A075269 A215602 * A359221 A228501 A089414

Adjacent sequences: A325625 A325626 A325627 * A325629 A325630 A325631

Keyword

nonn,more

Author

Manfred Scheucher and Günter Rote, Sep 07 2019

Status

approved