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A124219 a(n)= m-th positive divisor of n, where phi(n) is number of positive integers which are <= n and are coprime to n, d(n) is the number of positive divisors of n and m = d(n) if d(n)|phi(n), else m = phi(n) mod d(n).

%I A124219 #10 Oct 11 2019 11:15:10
%S A124219 1,1,3,2,5,2,7,8,9,10,11,4,13,2,15,4,17,18,19,2,21,2,23,24,5,26,3,28,
%T A124219 29,30,31,8,33,34,35,3,37,2,39,40,41,6,43,2,45,2,47,8,49,2,51,52,53,2,
%U A124219 55,56,57,58,59,4,61,2,63,8,65,6,67,2,69,70,71,72,73,74,15,76,77,78,79,2
%N A124219 a(n)= m-th positive divisor of n, where phi(n) is number of positive integers which are <= n and are coprime to n, d(n) is the number of positive divisors of n and m = d(n) if d(n)|phi(n), else m = phi(n) mod d(n).
%t A124219 f[n_] := Block[{d = Divisors[n]}, d[[Mod[EulerPhi[n], Length[d], 1]]]];Table[f[n], {n, 90}] (* _Ray Chandler_, Oct 26 2006 *)
%Y A124219 Cf. A000005, A000010, A124218, A124331.
%K A124219 nonn
%O A124219 1,3
%A A124219 _Leroy Quet_, Oct 19 2006
%E A124219 Edited and extended by _Ray Chandler_, Oct 26 2006