Number of n-element unlabeled ordered T_0-antichains; T_1-hypergraphs (with empty hyperedge but without multiple hyperedges) on n labeled nodes.
A059052
Number of n-element unlabeled ordered T_0-antichains; T_1-hypergraphs (with empty hyperedge but without multiple hyperedges) on n labeled nodes.
Terms
- a(0) =2a(1) =4a(2) =4a(3) =72a(4) =38040a(5) =4020463392
External references
- oeis: A059052