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A056276 Number of primitive (aperiodic) word structures of length n using a 5-ary alphabet. 0
1, 1, 4, 13, 51, 196, 854, 3830, 17997, 86419, 422004, 2079260, 10306751, 51263086, 255514299, 1275160060, 6368612301, 31821454413, 159042661904, 795019250650, 3974515029793, 19870830290476, 99348921288654, 496728909635860, 2483597478617750, 12417846151236799 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Permuting the alphabet will not change a word structure. Thus aabc and bbca have the same 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

Table of n, a(n) for n=1..26.

FORMULA

a(n) = Sum_{d|n} mu(d)*A056272(n/d).

CROSSREFS

Cf. A008683, A054720.

Sequence in context: A219579 A300122 A149461 * A144035 A056277 A082951

Adjacent sequences:  A056273 A056274 A056275 * A056277 A056278 A056279

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved

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Last modified May 19 11:13 EDT 2022. Contains 353833 sequences. (Running on oeis4.)