A056434 Number of step cyclic shifted sequence structures using exactly two different symbols.

0, 1, 1, 3, 2, 7, 4, 13, 10, 25, 14, 87, 36, 129, 183, 356, 260, 1345, 804, 3759, 4433, 9757, 8384, 47461, 33780, 108329, 138766, 408375, 331184, 2251815, 1155734

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..31.

Formula

A056429(n)-1.

Crossrefs

Column 2 of A288627.

Cf. A056415.

Sequence in context: A304882 A059029 A360968 * A143292 A293447 A382256

Adjacent sequences: A056431 A056432 A056433 * A056435 A056436 A056437

Keyword

nonn

Author

Marks R. Nester

Status

approved