Number of n-derangements that have an odd number of 2-cycles.
A248087
Number of n-derangements that have an odd number of 2-cycles.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =0a(4) =0a(5) =20a(6) =105a(7) =504a(8) =4480a(9) =43560a(10) =424305a(11) =4613840a(12) =55668096a(13) =724667580a(14) =10136511385a(15) =152029000200
External references
- oeis: A248087