Number of permutations p of 1,2,...,n satisfying |p(i+6)-p(i)|<>6 for all 1<=i<=n-6.
A189271
Number of permutations p of 1,2,...,n satisfying |p(i+6)-p(i)|<>6 for all 1<=i<=n-6.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =24a(4) =120a(5) =720a(6) =4800a(7) =34752a(8) =280512a(9) =2528256a(10) =25282560a(11) =278323200a(12) =3289036800a(13) =42336448512a(14) =589351062528
External references
- oeis: A189271