Number of 3-uniform hypergraphs on n unlabeled nodes, or equivalently number of relations with 3 arguments on n nodes.

A000665

Number of 3-uniform hypergraphs on n unlabeled nodes, or equivalently number of relations with 3 arguments on n nodes.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =34a(6) =2136a(7) =7013320

External references