|
| |
|
|
A056430
|
|
Number of step cyclic shifted sequence structures using a maximum of three different symbols.
|
|
4
|
|
|
|
1, 2, 3, 6, 6, 22, 16, 66, 83, 300, 296, 2243, 1778, 9780, 20640, 58428, 79554, 600798, 567544, 3671978, 6935746, 23785912, 31017008, 246156513, 282456333, 1357927400, 2615206733, 11358512518
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
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
|
Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = Sum_{k=1..3} A288627(n, k). - Andrew Howroyd, Jun 13 2017
|
|
|
CROSSREFS
|
Cf. A056411, A288627.
Sequence in context: A049297 A285664 A056391 * A089878 A057545 A015628
Adjacent sequences: A056427 A056428 A056429 * A056431 A056432 A056433
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Marks R. Nester
|
|
|
STATUS
|
approved
|
| |
|
|
