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 A255385 a(n) = sigma(n) + phi(n) - tau(n). 1
 1, 2, 4, 6, 8, 10, 12, 15, 16, 18, 20, 26, 24, 26, 28, 34, 32, 39, 36, 44, 40, 42, 44, 60, 48, 50, 54, 62, 56, 72, 60, 73, 64, 66, 68, 94, 72, 74, 76, 98, 80, 100, 84, 98, 96, 90, 92, 130, 96, 107, 100, 116, 104, 130, 108, 136, 112, 114, 116, 172, 120, 122 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS If n is prime or semiprime, then a(n) = 2n-2. LINKS FORMULA a(n) = A000203(n) + A000010(n) - A000005(n). a(n) = 2n - 2 + A153011(n). - Omar E. Pol, May 20 2015 MAPLE with(numtheory): A255385:=n->sigma(n)+phi(n)-tau(n): seq(A255385(n), n=1..100); MATHEMATICA Table[DivisorSigma[1, n] + EulerPhi[n] - DivisorSigma[0, n], {n, 100}] PROG (PARI) vector(100, n, sigma(n)+eulerphi(n)-numdiv(n)) \\ Derek Orr, May 05 2015 (MAGMA) [SumOfDivisors(n)+ EulerPhi(n)-NumberOfDivisors(n): n in [1..100]]; // Vincenzo Librandi, May 06 2015 CROSSREFS Cf. A000005 (tau), A000010 (phi), A000203 (sigma). Sequence in context: A264986 A140955 A111905 * A187412 A187473 A287122 Adjacent sequences:  A255382 A255383 A255384 * A255386 A255387 A255388 KEYWORD nonn,easy AUTHOR Wesley Ivan Hurt, May 05 2015 STATUS approved

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Last modified December 10 20:48 EST 2019. Contains 329909 sequences. (Running on oeis4.)