A056408 Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly four different symbols.

0, 0, 0, 1, 3, 37, 63, 478, 1316, 8594, 14619, 155961, 211231, 1732844, 5302820, 21559430, 43398413, 466493982, 625545865, 5659491433, 15126813702, 72778010746, 132561145173, 1460519397614, 2338565021379

Offset

1,5

Comments

See A056371 for an explanation of step shifts. 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

A056403(n)-A056402(n).

Crossrefs

Cf. A056388.

Sequence in context: A323829 A139842 A091824 * A056398 A092074 A183556

Adjacent sequences: A056405 A056406 A056407 * A056409 A056410 A056411

Keyword

nonn

Author

Marks R. Nester

Status

approved