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 Moebius strip.
A180503
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 Moebius strip.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =3a(8) =7a(9) =16a(10) =2a(11) =13a(12) =140a(13) =1499a(14) =11502a(15) =3a(16) =122a(17) =5589a(18) =245222a(19) =9186477a(20) =238834187
External references
- oeis: A180503