MATHEMATICA BOHEMICA, Vol. 125, No. 4, pp. 465-479, 2000

On the equation $\phi(|x^m-y^m|)=2^n$

Florian Luca

Florian Luca, FSP/Mathematik, Universitat Bielefeld, Postfach 10 01 31, 33501 Bielefeld, Germany, e-mail: fluca@Mathematik.Uni-Bielefeld.de

Abstract: In this paper we investigate the solutions of the equation in the title, where $\phi$ is the Euler function. We first show that it suffices to find the solutions of the above equation when $m=4$ and $x$ and $y$ are coprime positive integers. For this last equation, we show that aside from a few small solutions, all the others are in a one-to-one correspondence with the Fermat primes.

Keywords: Euler function, Fermat primes

Classification (MSC 1991): 11A25, 11A51, 11A63


Full text available as PDF (smallest), as compressed PostScript (.ps.gz) or as raw PostScript (.ps).

Access to the full text of journal articles on this site is restricted to the subscribers of Myris Trade. To activate your access, please contact Myris Trade at myris@myris.cz.


[Previous Article] [Next Article] [Contents of This Number] [Contents of Mathematica Bohemica]
[Full text of the older issues of Mathematica Bohemica at DML-CZ]