A056359 Number of bracelet structures using exactly four different colored beads.

0, 0, 0, 1, 2, 11, 33, 137, 478, 1851, 6845, 26148, 98406, 374010, 1416251, 5380907, 20440250, 77795428, 296384565, 1131011633, 4321964768, 16541275068, 63400061153, 243358803904, 935431121462, 3600520831215, 13876485252323, 53546253055179, 206864927506166, 800068244639812

Offset: 1

Author

Marks R. Nester

Keywords

• nonn

Comments

Turning over will not create a new bracelet. Permuting the colors of the beads will not change the structure.

References

• M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Links

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

Crossrefs

Column 4 of A152176.

Cf. A056297, A056353, A056354, A214309.

Formula

a(n) = A056354(n) - A056353(n).

Extensions

Terms a(27) and beyond from Andrew Howroyd, Oct 24 2019