Number of pairs of orientable necklaces with n beads and two colors; i.e., turning the necklace over does not leave it unchanged.
A059076
Number of pairs of orientable necklaces with n beads and two colors; i.e., turning the necklace over does not leave it unchanged.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =2a(8) =6a(9) =14a(10) =30a(11) =62a(12) =128a(13) =252a(14) =495a(15) =968a(16) =1866a(17) =3600a(18) =6917a(19) =13286a(20) =25476a(21) =48916a(22) =93837a(23) =180314a(24) =346554a(25) =666996a(26) =1284570a(27) =2477342a(28) =4781502a(29) =9240012
External references
- oeis: A059076