Number of n-element unlabeled connected N-free posets.
A202180
Number of n-element unlabeled connected N-free posets.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =31a(5) =115a(6) =474a(7) =2097a(8) =9967a(9) =50315a(10) =268442a(11) =1505463a(12) =8840306a(13) =54169431
External references
- oeis: A202180