A056445 Number of primitive (period n) step cyclic shifted sequence structures using exactly three different symbols.

0, 0, 1, 2, 3, 13, 11, 50, 71, 271, 281, 2139, 1741, 9639, 20452, 58019, 79293, 599367, 566739, 3667942, 6931300, 23775873, 31008623, 246106846, 282422549, 1357817329, 2615067894, 11358094490

Offset

1,4

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..28.

Formula

A056440(n)-A056439(n).

Crossrefs

Cf. A056425.

Sequence in context: A132365 A129671 A117684 * A171483 A100385 A250184

Adjacent sequences: A056442 A056443 A056444 * A056446 A056447 A056448

Keyword

nonn

Author

Marks R. Nester

Status

approved