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%I #20 Sep 08 2022 08:46:11
%S 1,2,4,6,8,10,12,15,16,18,20,26,24,26,28,34,32,39,36,44,40,42,44,60,
%T 48,50,54,62,56,72,60,73,64,66,68,94,72,74,76,98,80,100,84,98,96,90,
%U 92,130,96,107,100,116,104,130,108,136,112,114,116,172,120,122
%N a(n) = sigma(n) + phi(n) - tau(n).
%C If n is prime or semiprime, then a(n) = 2n-2.
%F a(n) = A000203(n) + A000010(n) - A000005(n).
%F a(n) = 2n - 2 + A153011(n). - _Omar E. Pol_, May 20 2015
%p with(numtheory): A255385:=n->sigma(n)+phi(n)-tau(n): seq(A255385(n), n=1..100);
%t Table[DivisorSigma[1, n] + EulerPhi[n] - DivisorSigma[0, n], {n, 100}]
%o (PARI) vector(100,n,sigma(n)+eulerphi(n)-numdiv(n)) \\ _Derek Orr_, May 05 2015
%o (Magma) [SumOfDivisors(n)+ EulerPhi(n)-NumberOfDivisors(n): n in [1..100]]; // _Vincenzo Librandi_, May 06 2015
%Y Cf. A000005 (tau), A000010 (phi), A000203 (sigma).
%K nonn,easy
%O 1,2
%A _Wesley Ivan Hurt_, May 05 2015
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