Number of permutations where every element in binary notation has ones at the same or adjacent positions of previous element's binary ones.

A115506

Number of permutations where every element in binary notation has ones at the same or adjacent positions of previous element's binary ones.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =8a(4) =24a(5) =168a(6) =840a(7) =1008a(8) =4032a(9) =32160a(10) =192960a(11) =1297440a(12) =9082080a(13) =126846720a(14) =1141620480a(15) =1243468800a(16) =4490307360a(17) =53812332000a(18) =526257365760

External references