Number of permutations p of {1,2,...,n} such that |p(i)-i| != 1 for all i.
A078480
Number of permutations p of {1,2,...,n} such that |p(i)-i| != 1 for all i.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =21a(6) =117a(7) =792a(8) =6205a(9) =55005a(10) =543597a(11) =5922930a(12) =70518905a(13) =910711193a(14) =12678337945a(15) =189252400480
External references
- oeis: A078480