On the composition of the Euler function and the sum of divisors function
Jean-Marie De Koninck ; Florian Luca
Colloquium Mathematicae, Tome 107 (2007), p. 31-51 / Harvested from The Polish Digital Mathematics Library
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Let H(n) = σ(ϕ(n))/ϕ(σ(n)), where ϕ(n) is Euler's function and σ(n) stands for the sum of the positive divisors of n. We obtain the maximal and minimal orders of H(n) as well as its average order, and we also prove two density theorems. In particular, we answer a question raised by Golomb.

Publié le : 2007-01-01
EUDML-ID : urn:eudml:doc:284003 
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Jean-Marie De Koninck; Florian Luca. On the composition of the Euler function and the sum of divisors function. Colloquium Mathematicae, Tome 107 (2007) pp. 31-51. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm108-1-4/