Number of permutations of 1..n with no adjacent pair summing to n+7.
A173847
Number of permutations of 1..n with no adjacent pair summing to n+7.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =720a(7) =5040a(8) =30240a(9) =282240a(10) =2338560a(11) =26853120a(12) =280143360a(13) =3802982400a(14) =47638886400a(15) =745007155200
External references
- oeis: A173847