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A326660
Number of n-bead asymmetric bracelets with exactly 3 different colored beads.
3
0, 0, 1, 3, 12, 34, 111, 315, 933, 2622, 7503, 21033, 59472, 167118, 472120, 1332945, 3777600, 10720869, 30516447, 87032994, 248820704, 712743768, 2045784183, 5882367570, 16942974048, 48876558318, 141204944529, 408494941773, 1183247473872, 3431450670601
OFFSET
1,4
COMMENTS
Asymmetric bracelets are those primitive (period n) bracelets that when turned over are different from themselves.
LINKS
FORMULA
a(n) = A032240(n) - 3*A032239(n) for n >= 3.
Moebius transform of A305542.
EXAMPLE
Case n = 4: There are 3 distinct asymmetric bracelets with exactly 3 colors which are aabc, abbc, abcc.
CROSSREFS
Column k=3 of A309651.
Sequence in context: A073372 A305023 A026573 * A225075 A293267 A295363
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Sep 12 2019
STATUS
approved