Number of permutations of 1..n with all differences of elements separated by distances 1 through 3 being respectively unique.
A170809
Number of permutations of 1..n with all differences of elements separated by distances 1 through 3 being respectively unique.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =12a(4) =40a(5) =116a(6) =200a(7) =444a(8) =864a(9) =3368a(10) =10936a(11) =38320a(12) =139848a(13) =534828a(14) =2230464a(15) =9802612a(16) =46188544a(17) =231210272a(18) =1213437504a(19) =6717614708a(20) =39002297800
External references
- oeis: A170809