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

A056383

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

Terms

    a(0) =4a(1) =12a(2) =36a(3) =144a(4) =276a(5) =2124a(6) =2796a(7) =17760a(8) =44184a(9) =263004a(10) =419868a(11) =4278000a(12) =5593996a(13) =44748804a(14) =134390724a(15) =539036160a(16) =1073758356a(17) =11453725416a(18) =15271054956a(19) =137575549680a(20) =366528035564

External references