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%I #15 Jul 26 2015 10:09:45
%S 5,1,2,2,3,2,6,3,5,3,10,3,12,7,5,9,16,5,18,7,10,12,22,7,18,13,16,11,
%T 28,6,30,15,17,16,22,11,36,18,22,13,40,10,42,17,20,20,46,14,42,15,30,
%U 19,52,15,34,20,35,24,58,11,60,25,34,26,41,16,66,25,44,15,70,20,72,29,33,30
%N a(n) = number of terms among {a(1), a(2), a(3), ..., a(n-1)} that are coprime to n; a(1)=5.
%C A family of related sequences can be generated using different positive integers for a(1). (a(1)=1 gives sequence A096216.)
%e a(8)=3 because among the first seven terms, namely 5,1,2,2,3,2,6, there are 3 terms that are relatively prime to 8 (5,1 and 3).
%p a[1]:=5: for n from 2 to 100 do s:=0: for j from 1 to n-1 do if gcd(a[j],n)=1 then s:=s+1 else s:=s fi od: a[n]:=s: od: seq(a[n],n=1..84); # _Emeric Deutsch_
%t a[1] = 5; a[n_] := a[n] = Count[ GCD[ Table[ a[i], {i, n - 1}], n], 1]; Array[a, 76] (* _Robert G. Wilson v_, Dec 27 2005 *)
%Y Cf. A096216.
%K nonn
%O 1,1
%A _Leroy Quet_, Aug 27 2004
%E More terms from _Emeric Deutsch_, Aug 03 2005
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