Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged.
A000048
Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =5a(7) =9a(8) =16a(9) =28a(10) =51a(11) =93a(12) =170a(13) =315a(14) =585a(15) =1091a(16) =2048a(17) =3855a(18) =7280a(19) =13797a(20) =26214a(21) =49929a(22) =95325a(23) =182361a(24) =349520a(25) =671088a(26) =1290555a(27) =2485504a(28) =4793490a(29) =9256395
External references
- oeis: A000048