## Values of Arithmetical Functions Equal to a Sum of Two Squares

Banks, William David, 1964-

Luca, Florian

Saidak, Filip

Shparlinski, Igor E.

##### Abstract

Let '(n) denote the Euler function. In this paper, we determine the order of growth for the number of positive integers n ≤ x for which
'(n) is the sum of two square numbers. We also obtain similar results for the Dedekind function (n) and the sum of divisors function _(n).

##### Part of

Mathematics publications (MU)

##### Citation

Quart. J. Math. Oxford Ser., 56 (2005), 123-139.