A325595 Number of symmetric Euclidean pseudo-order types: nondegenerate abstract order types of configurations of n points in the plane with a nontrivial automorphism.

0, 1, 1, 2, 3, 12, 30, 230, 849, 13434, 76200, 2392066

Offset: 1

Author

Manfred Scheucher and Günter Rote, Sep 07 2019

Keywords

• nonn
• more

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.

Crossrefs

Cf. A006247, A325628.

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