A056441 Number of primitive (period n) step cyclic shifted sequence structures using a maximum of four different symbols.

1, 1, 2, 5, 6, 29, 28, 142, 242, 1222, 1664, 15935, 18198, 134452, 376424, 1415060, 2634596, 26534337, 33499358, 287001476, 727425470, 3332039278, 5794658930, 61120838930, 93825569002, 601444720052

Offset

1,3

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..26.

Formula

sum mu(d)*A056431(n/d) where d|n.

Crossrefs

Cf. A056421.

Sequence in context: A214200 A273924 A008555 * A365085 A164805 A275285

Adjacent sequences: A056438 A056439 A056440 * A056442 A056443 A056444

Keyword

nonn

Author

Marks R. Nester

Status

approved