Number of 5-element families of an n-element set such that every 4 members of the family have a nonempty intersection.
A051367
Number of 5-element families of an n-element set such that every 4 members of the family have a nonempty intersection.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =224a(5) =21281a(6) =1144027a(7) =49310674a(8) =1915317642a(9) =70460566827
External references
- oeis: A051367