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%I #11 Sep 16 2015 04:59:05
%S 1,1,2,3,4,3,6,4,4,9,10,2,12,13,6,9,16,7,18,10,7,21,22,3,22,25,12,15,
%T 28,11,30,15,15,33,26,7,36,37,19,12,40,19,42,24,17,45,46,9,46,36,24,
%U 27,52,22,45,22,25,57,58,10,60,61,27,30,50,30,66,35,31,41,70,10,72,73,25,41
%N a(1)=1. a(n) = the number of earlier terms that are coprime to the n-th Fibonacci number.
%e 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.
%p 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
%t a = {1}; Do[AppendTo[a, Length[Select[a, GCD[ #, Fibonacci[Length[a] + 1]] == 1 &]]], {80}]; a (* _Stefan Steinerberger_, Oct 16 2007 *)
%K nonn
%O 1,3
%A _Leroy Quet_, Mar 13 2007
%E More terms from _Emeric Deutsch_, Mar 23 2007
%E More terms from _Stefan Steinerberger_, Oct 16 2007
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