Number of imprimitive (periodic) bracelets (or necklaces) with n red and blue beads such that the beads switch colors when bracelet is turned over.
A115123
Number of imprimitive (periodic) bracelets (or necklaces) with n red and blue beads such that the beads switch colors when bracelet is turned over.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =2a(4) =1a(5) =5a(6) =1a(7) =9a(8) =4a(9) =22a(10) =1a(11) =63a(12) =1a(13) =156a(14) =24a(15) =469a(16) =1a(17) =1532a(18) =1a(19) =4889a(20) =158a(21) =16546a(22) =1a(23) =57844a(24) =21a(25) =202061a(26) =1480a(27) =720533a(28) =1a(29) =2598406
External references
- oeis: A115123