On the functions φ(n) and σ(n)

Instytut Matematyczny Polskiej Akademii Nauk / Institute of Mathematics / Publishing house / Journals and Serials / Colloquium Mathematicum / All issues

A. Mąkowski, A. Schinzel Colloquium Mathematicum 13 (1964), 95-99 DOI: 10.4064/cm-13-1-95-99