Number of primitive (period n) step cyclic shifted sequences using exactly two different symbols.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =8a(6) =8a(7) =18a(8) =18a(9) =38a(10) =28a(11) =142a(12) =72a(13) =234a(14) =360a(15) =669a(16) =520a(17) =2606a(18) =1608a(19) =7338a(20) =8856a(21) =19370a(22) =16768a(23) =94308a(24) =67556a(25) =216200a(26) =277512a(27) =815310a(28) =662368a(29) =4499852