A328741 Number of n-bead necklace structures which are not self-equivalent under a nonzero rotation using exactly four different colored beads.

0, 0, 0, 0, 2, 9, 50, 206, 862, 3384, 13250, 50852, 194810, 741884, 2823712, 10735998, 40843370, 155483873, 592614050, 2261585918, 8643288808, 33080772468, 126797503250, 486710415710, 1870851589552, 7201012694120, 27752927349880, 107092389688830, 413729680838330

Offset: 1

Author

Andrew Howroyd, Oct 26 2019

Keywords

• nonn

Comments

Permuting the colors does not change the structure.

Examples

			For n=6, the 9 necklace structures are: aaabcd, aabacd, aabcad, aabbcd, aabcbd, aabcdb, aacbdb, ababcd, abacbd.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200

Crossrefs

Column 4 of A327693.

Cf. A056297, A056305, A328740, A328743.

Formula

a(p) = A056297(p) = A056305(p) for prime p.