A056358 Number of bracelet structures using exactly three different colored beads.

0, 0, 1, 2, 5, 14, 31, 82, 202, 538, 1401, 3838, 10395, 28890, 80207, 225368, 634265, 1796648, 5100325, 14535298, 41513434, 118880650, 341094843, 980665898, 2824223495, 8146908210, 23535345372, 68084937912, 197211483155, 571915789978, 1660402195255, 4825554617686

Offset

1,4

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) = A056353(n) - A000011(n).

Crossrefs

Column 3 of A152176.

Cf. A000011, A056296, A056353, A214307.

Sequence in context: A120328 A026011 A212393 * A336229 A296502 A036681

Adjacent sequences: A056355 A056356 A056357 * A056359 A056360 A056361

Keyword

nonn

Author

Marks R. Nester

Extensions

Terms a(28) and beyond from Andrew Howroyd, Oct 24 2019

Status

approved