login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056421 Number of primitive (period n) step cyclic shifted sequences using a maximum of four different symbols. 2
4, 6, 16, 45, 72, 404, 456, 2550, 5144, 26880, 38568, 367170, 431776, 3202964, 8993712, 33857520, 63177816, 636456776, 803796696, 6886253964, 17456593904, 79965511980, 139069427016, 1466861335900 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent.

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..24.

FORMULA

Sum mu(d)*A056412(n/d) where d|n.

CROSSREFS

Sequence in context: A227178 A165799 A231998 * A032295 A072279 A038236

Adjacent sequences:  A056418 A056419 A056420 * A056422 A056423 A056424

KEYWORD

nonn

AUTHOR

Marks R. Nester

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 30 18:49 EST 2020. Contains 338808 sequences. (Running on oeis4.)