Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.
A001883
Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =4a(6) =29a(7) =206a(8) =1708a(9) =15702a(10) =159737a(11) =1780696a(12) =21599745a(13) =283294740a(14) =3995630216a(15) =60312696452a(16) =970234088153
External references
- oeis: A001883