OFFSET
1,3
COMMENTS
About 60% of entries are of the form 4k+1; 20% are of the form 4k+2; 20% are of the form 4k+3. Obviously no term is divisible by 4. - Carmine Suriano, Feb 27 2014
Contains A030426 as a subsequence unless there exist Wall-Sun-Sun primes. - Max Alekseyev, Jan 04 2018
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1080 (terms 1..200 from Zak Seidov)
FORMULA
EXAMPLE
55 = 5 * 11 is a squarefree Fibonacci number.
MATHEMATICA
a={}; Do[f=Fibonacci[n]; If[SquareFreeQ[f], AppendTo[a, f]], {n, 1, 50}]; a (* Vladimir Joseph Stephan Orlovsky, Jul 22 2008 *)
Select[Fibonacci[Range[50]], SquareFreeQ] (* Harvey P. Dale, Aug 26 2021 *)
PROG
(PARI) { n=0; g=0; f=1; for (i=1, 500, if (issquarefree(g), write("b061305.txt", n++, " ", g)); if (n==200, break); s=f; f+=g; g=s ) } \\ Harry J. Smith, Jul 21 2009
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Amarnath Murthy, Apr 26 2001
EXTENSIONS
More terms from Asher Auel, May 14 2001
Mathematica updated by Jean-François Alcover, Jul 04 2013
STATUS
approved