Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 7).

A322297

Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 7).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =2a(8) =16a(9) =128a(10) =800a(11) =4160a(12) =18944a(13) =78080a(14) =301160a(15) =1208066a(16) =6753606a(17) =60823622a(18) =648980646a(19) =6581663766a(20) =60475366230a(21) =505780634070

External references