Number of imprimitive (periodic) n-bead necklaces with beads of 2 colors when turning over is allowed.

A115119

Number of imprimitive (periodic) n-bead necklaces with beads of 2 colors when turning over is allowed.

Terms

    a(0) =0a(1) =0a(2) =2a(3) =2a(4) =3a(5) =2a(6) =5a(7) =2a(8) =6a(9) =4a(10) =9a(11) =2a(12) =16a(13) =2a(14) =19a(15) =10a(16) =30a(17) =2a(18) =55a(19) =2a(20) =81a(21) =20a(22) =127a(23) =2a(24) =248a(25) =8a(26) =381a(27) =46a(28) =690a(29) =2

External references