Triangle read by row. T(n,m) gives the number of isomorphism classes of simple arrangements of n pseudolines and m double pseudolines in the projective plane.
A180500
Triangle read by row. T(n,m) gives the number of isomorphism classes of simple arrangements of n pseudolines and m double pseudolines in the projective plane.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =2a(8) =4a(9) =13a(10) =1a(11) =5a(12) =48a(13) =626a(14) =6570a(15) =1a(16) =25a(17) =1329a(18) =86715a(19) =4822394a(20) =181403533
External references
- oeis: A180500