Number of simple arrangements of n pseudolines in the projective plane with a marked cell. Number of Euclidean pseudo-order types: nondegenerate abstract order types of configurations of n points in the plane.

A006247

Number of simple arrangements of n pseudolines in the projective plane with a marked cell. Number of Euclidean pseudo-order types: nondegenerate abstract order types of configurations of n points in the plane.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =16a(6) =135a(7) =3315a(8) =158830a(9) =14320182a(10) =2343203071a(11) =691470685682

External references