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A163370
a(n) = phi(sigma(phi(n))).
2
1, 1, 2, 2, 6, 2, 4, 6, 4, 6, 6, 6, 12, 4, 8, 8, 30, 4, 24, 8, 12, 6, 12, 8, 12, 12, 24, 12, 24, 8, 24, 30, 12, 30, 16, 12, 72, 24, 16, 30, 24, 12, 32, 12, 16, 12, 24, 30, 32, 12, 36, 16, 42, 24, 24, 16, 72, 24, 24, 30, 48, 24, 72, 36, 60, 12, 48, 36, 24, 16
OFFSET
1,3
COMMENTS
LINKS
MAPLE
with(numtheory): A163370:=n->phi(sigma(phi(n))): seq(A163370(n), n=1..100); # Wesley Ivan Hurt, Dec 19 2016
MATHEMATICA
EulerPhi[DivisorSigma[1, EulerPhi[Range[80]]]] (* Harvey P. Dale, Dec 24 2012 *)
PROG
(PARI) vector(50, n, eulerphi(sigma(eulerphi(n)))) \\ G. C. Greubel, Dec 19 2016
(Magma) [EulerPhi(SumOfDivisors(EulerPhi(n))): n in [1..80]]; // Vincenzo Librandi, Dec 21 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaroslav Krizek, Jul 25 2009
EXTENSIONS
More terms from Harvey P. Dale, Dec 24 2012
STATUS
approved