Number of step shifted (decimated) sequences using a maximum of four different symbols.

A056373

Number of step shifted (decimated) sequences using a maximum of four different symbols.

Terms

    a(0) =4a(1) =16a(2) =40a(3) =160a(4) =280a(5) =2176a(6) =2800a(7) =17920a(8) =44224a(9) =263296a(10) =419872a(11) =4280320a(12) =5594000a(13) =44751616a(14) =134391040a(15) =539054080a(16) =1073758360a(17) =11453771776a(18) =15271054960a(19) =137575813120a(20) =366528038400

External references