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A056268 Number of primitive (aperiodic) words of length n which contain exactly three different symbols. 1
0, 0, 6, 36, 150, 534, 1806, 5760, 18144, 55830, 17100, 6, 518580, 1569750, 4732014, 14250450, 42844320, 128746950, 38661, 5376, 1160688606, 3483582660, 10454059938, 31368305694, 941180, 13006, 282378679920 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

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

Table of n, a(n) for n=1..27.

FORMULA

sum mu(d)*A001117(n/d) where d|n.

CROSSREFS

Cf. A000244, A001117, A054718.

Sequence in context: A181478 A223841 A210322 * A001117 A224149 A055404

Adjacent sequences:  A056265 A056266 A056267 * A056269 A056270 A056271

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved

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Last modified August 10 16:56 EDT 2020. Contains 336381 sequences. (Running on oeis4.)