Number of permutations p of [n] such that the n-1 sums p(i)+p(i+1) (i=1,2,...n-1) are all distinct.
A091217
Number of permutations p of [n] such that the n-1 sums p(i)+p(i+1) (i=1,2,...n-1) are all distinct.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =16a(5) =54a(6) =232a(7) =1132a(8) =6024a(9) =36262a(10) =242080a(11) =1775316a(12) =14135584a(13) =122077832a(14) =1131066448a(15) =11230979624a(16) =118638940864
External references
- oeis: A091217