|
|
A288628
|
|
Number of step cyclic shifted sequence structures of length n using an infinite alphabet.
|
|
2
|
|
|
1, 2, 3, 7, 8, 37, 37, 223, 468, 3203, 6398, 93103, 178663, 2282131, 11561896, 82120878, 304719416, 6316222138, 17055376113, 323332552319, 1884432112761, 20485110860448, 87256977757852, 2322728266726152, 9277181270824996, 159074512149044084, 1122874592283076868
(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
|
|
|
PROG
|
(PARI) \\ see A056391 for Polya enumeration functions
a(n) = NonequivalentStructs(CyclicStepShiftPerms(n), n); \\ Andrew Howroyd, Oct 14 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|