a(n) is the number of inequivalent permutations of {0..2n-1}, such that the first differences (modulo 2n) are a permutation of {1..2n-1}.

A067601

a(n) is the number of inequivalent permutations of {0..2n-1}, such that the first differences (modulo 2n) are a permutation of {1..2n-1}.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =12a(4) =144a(5) =1928a(6) =44664a(7) =1377984a(8) =51826560

External references