OFFSET
1,4
COMMENTS
For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome.
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
FORMULA
a(n) = Sum_{d|n} mu(d)*A056489(n/d).
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Terms a(32) and beyond from Andrew Howroyd, Sep 28 2019
STATUS
approved