Number of set-systems covering a subset of {1..n} where every two covered vertices appear together in some edge (cointersecting).

A327039

Number of set-systems covering a subset of {1..n} where every two covered vertices appear together in some edge (cointersecting).

Terms

    a(0) =1a(1) =2a(2) =7a(3) =88a(4) =25421a(5) =2077323118

External references