Number of n-bead necklace structures which are not self-equivalent under a nonzero rotation using exactly four different colored beads.

A328741

Number of n-bead necklace structures which are not self-equivalent under a nonzero rotation using exactly four different colored beads.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =9a(6) =50a(7) =206a(8) =862a(9) =3384a(10) =13250a(11) =50852a(12) =194810a(13) =741884a(14) =2823712a(15) =10735998a(16) =40843370a(17) =155483873a(18) =592614050a(19) =2261585918a(20) =8643288808a(21) =33080772468a(22) =126797503250a(23) =486710415710

External references