Number of simple arrangements of pseudolines in the projective plane with an oriented marked cell; number of oriented abstract order types of n points (distinguishing mirror-symmetric copies).
A006246
Number of simple arrangements of pseudolines in the projective plane with an oriented marked cell; number of oriented abstract order types of n points (distinguishing mirror-symmetric copies).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =20a(6) =242a(7) =6405a(8) =316835a(9) =28627261a(10) =4686329954
External references
- oeis: A006246