Geodesic
On the equation \(\sigma(n) = n + \varphi(n)\)
Journal of integer sequences, Tome 20 (2017) no. 6
In this paper we consider the equation $\sigma (n) = n + \phi (n)$, for which $n = 2$ is the only known solution. We provide necessary conditions for the existence of any larger solutions.
Classification : 11A25
Keywords: sum of divisors, Euler totient 
@article{JIS_2017__20_6_a5,
     author = {Iannucci,  Douglas E.},
     title = {On the equation \(\sigma(n) = n + \varphi(n)\)},
     journal = {Journal of integer sequences},
     year = {2017},
     volume = {20},
     number = {6},
     zbl = {1422.11005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2017__20_6_a5/}
}
TY  - JOUR
AU  - Iannucci,  Douglas E.
TI  - On the equation \(\sigma(n) = n + \varphi(n)\)
JO  - Journal of integer sequences
PY  - 2017
VL  - 20
IS  - 6
UR  - http://geodesic.mathdoc.fr/item/JIS_2017__20_6_a5/
LA  - en
ID  - JIS_2017__20_6_a5
ER  - 
%0 Journal Article
%A Iannucci,  Douglas E.
%T On the equation \(\sigma(n) = n + \varphi(n)\)
%J Journal of integer sequences
%D 2017
%V 20
%N 6
%U http://geodesic.mathdoc.fr/item/JIS_2017__20_6_a5/
%G en
%F JIS_2017__20_6_a5
Iannucci,  Douglas E. On the equation \(\sigma(n) = n + \varphi(n)\). Journal of integer sequences, Tome 20 (2017) no. 6. http://geodesic.mathdoc.fr/item/JIS_2017__20_6_a5/