Number of nonisomorphic systems enumerated by A102894; that is, the number of inequivalent closure operators in which the empty set is closed. Also, the number of union-closed sets with n elements that contain the universe and the empty set.
A108798
Number of nonisomorphic systems enumerated by A102894; that is, the number of inequivalent closure operators in which the empty set is closed. Also, the number of union-closed sets with n elements that contain the universe and the empty set.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =14a(4) =165a(5) =14480a(6) =108281182
External references
- oeis: A108798