OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
MAPLE
with(numtheory): A163372:=n->sigma(phi(sigma(n))): seq(A163372(n), n=1..100); # Wesley Ivan Hurt, Oct 06 2017
MATHEMATICA
DivisorSigma[1, EulerPhi[DivisorSigma[1, Range[100]]]] (* G. C. Greubel, Dec 20 2016 *)
PROG
(PARI) vector(80, n, sigma(eulerphi(sigma(n)))) \\ Michel Marcus, Jul 31 2015
(Magma) [SumOfDivisors(EulerPhi(SumOfDivisors(n))): n in [1..80]]; // Vincenzo Librandi, Dec 20 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jul 25 2009
EXTENSIONS
More terms from Michel Marcus, Jul 31 2015
STATUS
approved