Number of simple mixed arrangements of n pseudolines and 1 double pseudoline in the projective plane.
A191951
Number of simple mixed arrangements of n pseudolines and 1 double pseudoline in the projective plane.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =25a(5) =302a(6) =9194a(7) =556298
External references
- oeis: A191951