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%I A353646 #15 May 07 2022 09:42:52
%S A353646 1,2,1,3,1,2,2,2,2,3,2,3,1,4,1,15,3,4,4,3,4,6,4,2,3,1,8,2,2,3,8,9,4,9,
%T A353646 2,6,1,8,1,3,3,8,10,6,1,12,8,15,6,3,3,7,9,16,3,4,8,6,8,3,1,16,4,63,1,
%U A353646 12,16,9,8,2,12,4,1,1,3,4,8,2,16,15,55,9,12,4,9,20,4,6,3,3,2,12,16,24,4,9,7,18,4,9
%N A353646 a(n) = phi(sigma(n)) / gcd(phi(n), phi(sigma(n))).
%C A353646 Numerator of ratio A062401(n) / A000010(n), phi(sigma(n)) / phi(n).
%H A353646 Antti Karttunen, <a href="/A353646/b353646.txt">Table of n, a(n) for n = 1..16384</a>
%H A353646 Antti Karttunen, <a href="/A353646/a353646.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%H A353646 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A353646 a(n) = A062401(n) / A353643(n) = A062401(n) / gcd(A062401(n), A353636(n)).
%t A353646 a[n_] := (phi = EulerPhi[DivisorSigma[1, n]])/GCD[EulerPhi[n], phi]; Array[a, 100] (* _Amiram Eldar_, May 06 2022 *)
%o A353646 (PARI) A353646(n) = { my(ps=eulerphi(sigma(n))); (ps / gcd(eulerphi(n), ps)); };
%Y A353646 Cf. A000010, A000203, A062401, A353636, A353637, A353643, A353644 (denominators).
%K A353646 nonn,frac
%O A353646 1,2
%A A353646 _Antti Karttunen_, May 06 2022

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