Number of step cyclic shifted sequences using exactly two different symbols.

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =4a(5) =11a(6) =8a(7) =22a(8) =20a(9) =43a(10) =28a(11) =156a(12) =72a(13) =243a(14) =366a(15) =691a(16) =520a(17) =2635a(18) =1608a(19) =7384a(20) =8866a(21) =19399a(22) =16768a(23) =94482a(24) =67560a(25) =216273a(26) =277532a(27) =815556a(28) =662368a(29) =4500265