Number of binary relations on n unlabeled nodes that are neither reflexive nor antireflexive.
A309980
Number of binary relations on n unlabeled nodes that are neither reflexive nor antireflexive.
Terms
- a(0) =0a(1) =4a(2) =72a(3) =2608a(4) =272752a(5) =93847104a(6) =110518842048
External references
- oeis: A309980