Number of set-systems covering n vertices, every two of which appear together in some edge (cointersecting).
A327040
Number of set-systems covering n vertices, every two of which appear together in some edge (cointersecting).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =72a(4) =25104a(5) =2077196832
External references
- oeis: A327040