A056438 - OEIS

A056438

Number of step cyclic shifted sequence structures using exactly six different symbols.

0, 0, 0, 0, 0, 1, 1, 18, 59, 630, 1681, 28867, 60083, 757577, 3514504, 21424002, 64372109, 1024999230, 2026631203, 26920955243, 105501588415, 742299898741, 1974251382095, 31721456317841, 74052852505684

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OFFSET

1,8

COMMENTS

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. Permuting the symbols will not change the 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..25.

FORMULA

A056433(n)-A056432(n).

CROSSREFS

Column 6 of A288627.

Cf. A056419.

Sequence in context: A244806 A027055 A056448 * A218617 A105521 A154563

Adjacent sequences: A056435 A056436 A056437 * A056439 A056440 A056441

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved