Number of 2n-bead black-white reversible complementable necklaces with n black beads and fundamental period 2n.
A045633
Number of 2n-bead black-white reversible complementable necklaces with n black beads and fundamental period 2n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =12a(6) =31a(7) =84a(8) =250a(9) =762a(10) =2504a(11) =8358a(12) =28928a(13) =101339a(14) =361184a(15) =1297864a(16) =4707712a(17) =17179434a(18) =63068079a(19) =232615770a(20) =861723271a(21) =3204236692a(22) =11955827898a(23) =44748176652a(24) =167959114814a(25) =632058070297
External references
- oeis: A045633