OFFSET
1,3
COMMENTS
A sequence is squarefree if it has no subsequence of the form XX.
Is this sequence unbounded?
LINKS
FORMULA
Apparently, a(3*k+1) = 0 for any k >= 0.
EXAMPLE
For n = 1:
- "0" is squarefree,
- hence a(1) = 0.
For n = 2:
- "00" is not squarefree,
- "01" and "1" are squarefree,
- hence a(2) = 1.
For n = 3:
- "010" is squarefree but "00" is not,
- "011" is not squarefree,
- "012" and "02" are squarefree,
- hence a(3) = 2.
For n = 4:
- "0120" and "10" are squarefree,
- hence a(4) = 0.
PROG
(C) See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jul 06 2019
STATUS
approved