a(n) is the number of ways to make a Secret Santa assignment among n couples such that no one gets their partner's name and if A gets B's name, B does not get A's name.
A367537
a(n) is the number of ways to make a Secret Santa assignment among n couples such that no one gets their partner's name and if A gets B's name, B does not get A's name.
Terms
- a(0) =0a(1) =2a(2) =48a(3) =2652a(4) =251328a(5) =34213080a(6) =6362490816
External references
- oeis: A367537