A056395 Number of step shifted (decimated) sequence structures using a maximum of six different symbols.

1, 2, 4, 11, 18, 117, 161, 1193, 3530, 27569, 60333, 863409, 1636609, 19122031, 84580125, 501915567, 1492170609, 23751685183, 47340359591, 637742820401, 2546703019245, 18317620839483, 49923584451715

Offset: 1

Author

Marks R. Nester

Keywords

• nonn

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]

Crossrefs

Cf. A056375.

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.