Number of primitive (period n) n-bead necklace structures using exactly three different colored beads.

A056304

Number of primitive (period n) n-bead necklace structures using exactly three different colored beads.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =2a(4) =5a(5) =17a(6) =43a(7) =124a(8) =338a(9) =941a(10) =2591a(11) =7234a(12) =20125a(13) =56407a(14) =158349a(15) =446492a(16) =1262225a(17) =3580330a(18) =10181479a(19) =29031306a(20) =82968799a(21) =237642659a(22) =682014587a(23) =1960974220a(24) =5647919640a(25) =16292741605a(26) =47069104274a(27) =136166647110a(28) =394418199725

External references