Number of partial order-preserving or -reversing transformations of a chain of length n.
A371698
Number of partial order-preserving or -reversing transformations of a chain of length n.
Terms
- a(0) =2a(1) =9a(2) =54a(3) =323a(4) =1848a(5) =10293a(6) =56738a(7) =312327a(8) =1723692a(9) =9549785a(10) =53121654a(11) =296593547a(12) =1661423104a(13) =9333552509a(14) =52565738570a(15) =296696569871
External references
- oeis: A371698