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A056358
Number of bracelet structures using exactly three different colored beads.
5
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
FORMULA
a(n) = A056353(n) - A000011(n).
CROSSREFS
Column 3 of A152176.
Sequence in context: A120328 A026011 A212393 * A336229 A296502 A036681
KEYWORD
nonn
EXTENSIONS
Terms a(28) and beyond from Andrew Howroyd, Oct 24 2019
STATUS
approved