Number of permutations p of 1,2,...,n satisfying |p(i+2)-p(i)| not equal to 2 for all 0<i<n-1.
A110128
Number of permutations p of 1,2,...,n satisfying |p(i+2)-p(i)| not equal to 2 for all 0<i<n-1.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =16a(5) =44a(6) =200a(7) =1288a(8) =9512a(9) =78652a(10) =744360a(11) =7867148a(12) =91310696a(13) =1154292796a(14) =15784573160a(15) =232050062524
External references
- oeis: A110128