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 A163379 a(n) = phi(phi(tau(n))). 2
 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,16 LINKS G. C. Greubel, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A000010(A000010(A000005(n))) = A000010(A163109(n)) = A010554(A000005(n)). MATHEMATICA EulerPhi[EulerPhi[DivisorSigma[0, Range[100]]]] (* G. C. Greubel, Dec 20 2016 *) PROG (PARI) vector(100, n, eulerphi(eulerphi(numdiv(n)))) \\ G. C. Greubel, Dec 20 2016 CROSSREFS Cf. A000005, A000010, A010554, A163109. Sequence in context: A328856 A053150 A295657 * A006466 A316439 A335078 Adjacent sequences:  A163376 A163377 A163378 * A163380 A163381 A163382 KEYWORD nonn AUTHOR Jaroslav Krizek, Jul 25 2009 EXTENSIONS More terms added by G. C. Greubel, Dec 20 2016 STATUS approved

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Last modified September 18 16:05 EDT 2020. Contains 337169 sequences. (Running on oeis4.)