Number of cyclic binary sequences of length n containing no abelian 4th powers.

Terms

a(0) =2a(1) =3a(2) =4a(3) =4a(4) =4a(5) =8a(6) =10a(7) =14a(8) =12a(9) =20a(10) =34a(11) =33a(12) =52a(13) =61a(14) =76a(15) =96a(16) =126a(17) =200a(18) =258a(19) =442a(20) =568a(21) =889a(22) =1224a(23) =1264a(24) =1020a(25) =1697a(26) =2394a(27) =3672a(28) =4500a(29) =9257