Number of finite sets of set partitions of {1,...,n} such that any two have meet {{1},...,{n}} and join {{1,...,n}}.

A318532

Number of finite sets of set partitions of {1,...,n} such that any two have meet {{1},...,{n}} and join {{1,...,n}}.

Terms

    a(0) =2a(1) =4a(2) =11a(3) =51a(4) =635a(5) =15591

External references