OFFSET
1,8
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..200
EXAMPLE
For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome. Permuting the symbols will not change the structure.
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Corrected by T. D. Noe, Oct 25 2006
a(17)-a(30) from Andrew Howroyd, Apr 08 2017
Terms a(31) and beyond from Andrew Howroyd, Oct 01 2019
STATUS
approved