OFFSET
1,2
COMMENTS
A word w is bordered if it has a nonempty prefix, unequal to w, that is also a suffix. A word is unbordered if it is not bordered.
EXAMPLE
For n = 5, the 6 words that are not so expressible are 00000, 00100, 01010, and their complements.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Mar 07 2019
EXTENSIONS
a(23)-a(37) from Bert Dobbelaere, Mar 24 2019
STATUS
approved