Number of commuting pairs of equivalence relations on [n].

A354458

Number of commuting pairs of equivalence relations on [n].

Terms

    a(0) =1a(1) =1a(2) =4a(3) =19a(4) =117a(5) =864a(6) =7459a(7) =73749a(8) =818960a(9) =10078023

External references