Positive integers $n$ such that $\sigma \left(\varphi \right(n\left)\right)=\sigma \left(n\right)$.

De Koninck, Jean-Marie, and Luca, Florian. "Positive integers such that .." Journal of Integer Sequences [electronic only] 11.1 (2008): Article 08.1.5, 14 p., electronic only-Article 08.1.5, 14 p., electronic only. <http://eudml.org/doc/45182>.

@article{DeKoninck2008,
author = {De Koninck, Jean-Marie, Luca, Florian},
journal = {Journal of Integer Sequences [electronic only]},
keywords = {Euler's function; sum of divisors},
language = {eng},
number = {1},
pages = {Article 08.1.5, 14 p., electronic only-Article 08.1.5, 14 p., electronic only},
publisher = {School of Computer Science, University of Waterloo, Waterloo},
title = {Positive integers such that .},
url = {http://eudml.org/doc/45182},
volume = {11},
year = {2008},
}

TY - JOUR
AU - De Koninck, Jean-Marie
AU - Luca, Florian
TI - Positive integers such that .
JO - Journal of Integer Sequences [electronic only]
PY - 2008
PB - School of Computer Science, University of Waterloo, Waterloo
VL - 11
IS - 1
SP - Article 08.1.5, 14 p., electronic only
EP - Article 08.1.5, 14 p., electronic only
LA - eng
KW - Euler's function; sum of divisors
UR - http://eudml.org/doc/45182
ER -