Number of circular permutations of {1, 2, ..., n}, where every next element in binary notation has ones at the same or adjacent positions of previous element's binary ones.

A115507

Number of circular permutations of {1, 2, ..., n}, where every next element in binary notation has ones at the same or adjacent positions of previous element's binary ones.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =1a(4) =2a(5) =18a(6) =72a(7) =42a(8) =126a(9) =1080a(10) =5400a(11) =42240a(12) =253440a(13) =3578400a(14) =28627200a(15) =16914240a(16) =54396720a(17) =620978400a(18) =5417102880a(19) =40328285760a(20) =322626286080

External references