OFFSET
1,3
EXAMPLE
The 8th Fibonacci number is 21. There are four terms from among the first 8 terms that are coprime to 21: a(1)=1, a(2)=1, a(3)=2 and a(5)=4. So a(8) = 4.
MAPLE
with(combinat): a:=proc(n) local ct, j: if n=1 then ct:=1: else ct:=0: for j from 1 to n-1 do if gcd(fibonacci(n), a(j))=1 then ct:=ct+1 else ct:=ct fi: od: fi: ct; end: seq(a(n), n=1..18); # Emeric Deutsch, Mar 23 2007
MATHEMATICA
a = {1}; Do[AppendTo[a, Length[Select[a, GCD[ #, Fibonacci[Length[a] + 1]] == 1 &]]], {80}]; a (* Stefan Steinerberger, Oct 16 2007 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Mar 13 2007
EXTENSIONS
More terms from Emeric Deutsch, Mar 23 2007
More terms from Stefan Steinerberger, Oct 16 2007
STATUS
approved