OFFSET
1,8
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
Andrew Howroyd, Table of n, a(n) for n = 1..1275
EXAMPLE
Triangle begins
1;
1, 1;
1, 1, 1;
1, 3, 2, 1;
1, 2, 3, 1, 1;
1, 7, 14, 11, 3, 1;
1, 4, 11, 13, 6, 1, 1;
1, 13, 52, 83, 52, 18, 3, 1;
1, 10, 72, 162, 148, 59, 13, 2, 1;
1, 25, 274, 930, 1140, 630, 171, 28, 3, 1;
...
PROG
(PARI) \\ see A056391 for Polya enumeration functions
T(n, k) = NonequivalentStructsExactly(CyclicStepShiftPerms(n), k); \\ Andrew Howroyd, Oct 14 2017
CROSSREFS
Row sums are A288628.
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, Jun 11 2017
STATUS
approved