Number of non-isomorphic sets of subsets of {1..n} that are closed under union and cover all n vertices. First differences of A193675.
A326907
Number of non-isomorphic sets of subsets of {1..n} that are closed under union and cover all n vertices. First differences of A193675.
Terms
- a(0) =2a(1) =2a(2) =6a(3) =28a(4) =330a(5) =28960a(6) =216562364
External references
- oeis: A326907