a(n) is the number of complement pairs of primitive 2n-bead balanced binary necklaces.

A383904

a(n) is the number of complement pairs of primitive 2n-bead balanced binary necklaces.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =3a(5) =11a(6) =35a(7) =118a(8) =392a(9) =1336a(10) =4587a(11) =15986a(12) =56231a(13) =199854a(14) =716014a(15) =2584742a(16) =9390656a(17) =34315811a(18) =126039218a(19) =465062362a(20) =1723066193a(21) =6407806833a(22) =23910159818a(23) =89493721076a(24) =335912335304

External references