Number of n-element unlabeled ordered T_0-antichains without isolated vertices; number of T_1-hypergraphs (without empty edge and without multiple edges) on n labeled vertices.
A059523
Number of n-element unlabeled ordered T_0-antichains without isolated vertices; number of T_1-hypergraphs (without empty edge and without multiple edges) on n labeled vertices.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =36a(4) =19020a(5) =2010231696
External references
- oeis: A059523