A056420 - OEIS

A056420

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

3, 3, 7, 15, 21, 79, 75, 306, 433, 1605, 1695, 12662, 10461, 57759, 122791, 347895, 476049, 3596917, 3401967, 22005312, 41597289, 142675887, 186077883, 1476684552, 1694657979, 8147271993, 15690973311

(list; graph; refs; listen; history; text; internal format)

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..27.

FORMULA

Sum mu(d)*A056411(n/d) where d|n.

CROSSREFS

Sequence in context: A218242 A218288 A356976 * A030069 A004043 A104176

Adjacent sequences: A056417 A056418 A056419 * A056421 A056422 A056423

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved