Number of chains of 2-element subsets of {0,1, 2, ..., n} that contain no consecutive integers.
A330302
Number of chains of 2-element subsets of {0,1, 2, ..., n} that contain no consecutive integers.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =51a(4) =18731a(5) =408990251
External references
- oeis: A330302