Number of 2n-bead black-white complementable necklaces with n black beads and fundamental period 2n.

A045632

Number of 2n-bead black-white complementable necklaces with n black beads and fundamental period 2n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =14a(6) =40a(7) =127a(8) =408a(9) =1364a(10) =4638a(11) =16079a(12) =56401a(13) =200169a(14) =716599a(15) =2585833a(16) =9392704a(17) =34319666a(18) =126046498a(19) =465076159a(20) =1723092407a(21) =6407856762a(22) =23910255143a(23) =89493903437a(24) =335912684824

External references