A056421 - OEIS

A056421

Number of primitive (period n) step cyclic shifted sequences using a maximum of four different symbols.

4, 6, 16, 45, 72, 404, 456, 2550, 5144, 26880, 38568, 367170, 431776, 3202964, 8993712, 33857520, 63177816, 636456776, 803796696, 6886253964, 17456593904, 79965511980, 139069427016, 1466861335900

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OFFSET

1,1

COMMENTS

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent.

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..24.

FORMULA

Sum mu(d)*A056412(n/d) where d|n.

CROSSREFS

Sequence in context: A227178 A165799 A231998 * A032295 A072279 A038236

Adjacent sequences: A056418 A056419 A056420 * A056422 A056423 A056424

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved