Number of primitive (period n) step cyclic shifted sequences using a maximum of four different symbols.

A056421

Number of primitive (period n) step cyclic shifted sequences using a maximum of four different symbols.

Terms

    a(0) =4a(1) =6a(2) =16a(3) =45a(4) =72a(5) =404a(6) =456a(7) =2550a(8) =5144a(9) =26880a(10) =38568a(11) =367170a(12) =431776a(13) =3202964a(14) =8993712a(15) =33857520a(16) =63177816a(17) =636456776a(18) =803796696a(19) =6886253964a(20) =17456593904a(21) =79965511980a(22) =139069427016

External references