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

1,5

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

Formula

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

Crossrefs

Column 4 of A152176.

Cf. A056297, A056353, A056354, A214309.

Sequence in context: A034128 A034427 A056368 * A088306 A100109 A328152

Adjacent sequences: A056356 A056357 A056358 * A056360 A056361 A056362

Keyword

nonn

Author

Marks R. Nester

Extensions

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

Status

approved