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%I #12 Sep 08 2022 08:45:13
%S -1,1,5,8,14,22,25,31,28,48,56,73,78,76,56,80,74,138,112,120,159,136,
%T 102,156,210,185,168,126,240,212,248,212,226,240,226,300,314,283,204,
%U 252,222,474,296,412,339,388,472,360,270,472,378,368,634,396,427,316,404,592,534,628,436,434,582,480,684,456,700,836
%N a(n) = A065395(A000040(n)); values of commutator of sigma and phi function at prime number arguments.
%C The sequence differs from A065394 since it is not monotonic.
%e a(1) = sigma(phi(2))- phi(sigma(2)) = sigma(1)-phi(3) = 1-2 = -1.
%o (Magma) [DivisorSigma(1,EulerPhi(p))-EulerPhi(DivisorSigma(1,p)): p in PrimesUpTo(400)]; // _Bruno Berselli_, Oct 20 2015
%Y Cf. A000010, A000040, A000203, A033632, A065393-A065395, A092584-A092589.
%K sign,look
%O 1,3
%A _Labos Elemer_, Mar 03 2004
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