Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly four different symbols.

A056408

Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly four different symbols.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =3a(5) =37a(6) =63a(7) =478a(8) =1316a(9) =8594a(10) =14619a(11) =155961a(12) =211231a(13) =1732844a(14) =5302820a(15) =21559430a(16) =43398413a(17) =466493982a(18) =625545865a(19) =5659491433a(20) =15126813702a(21) =72778010746a(22) =132561145173

External references