@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/}
}