Number of permutations of 1..n with the sum of squared adjacent differences <= n*(n-1)/2.

A180068

Number of permutations of 1..n with the sum of squared adjacent differences <= n*(n-1)/2.

Terms

    a(0) =2a(1) =2a(2) =6a(3) =16a(4) =34a(5) =140a(6) =508a(7) =2100a(8) =9386a(9) =44398a(10) =214410a(11) =1103178a(12) =6002116a(13) =33772692a(14) =196340714a(15) =1190396084a(16) =7486976948a(17) =48456599516a(18) =322526380686

External references