Number of permutations P of 1..n such that in P and in the inverse of P, every pair of adjacent numbers and the first and last number, are relatively prime.
A117542
Number of permutations P of 1..n such that in P and in the inverse of P, every pair of adjacent numbers and the first and last number, are relatively prime.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =8a(4) =36a(5) =16a(6) =127a(7) =320a(8) =581a(9) =1564a(10) =13565a(11) =13760a(12) =149186a(13) =773727a(14) =540538
External references
- oeis: A117542