Number of unlabeled set-systems (without {}) on n vertices that are closed under intersection.
A326904
Number of unlabeled set-systems (without {}) on n vertices that are closed under intersection.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =10a(4) =38a(5) =368a(6) =29328a(7) =216591692
External references
- oeis: A326904