On a conjecture of Mąkowski and Schinzel

Graeme Cohen

Colloquium Mathematicae (1997)

  • Volume: 74, Issue: 1, page 1-8
  • ISSN: 0010-1354

How to cite


Cohen, Graeme. "On a conjecture of Mąkowski and Schinzel." Colloquium Mathematicae 74.1 (1997): 1-8. <http://eudml.org/doc/210499>.

author = {Cohen, Graeme},
journal = {Colloquium Mathematicae},
keywords = {Fermat numbers; sum of divisors function; Euler's function},
language = {eng},
number = {1},
pages = {1-8},
title = {On a conjecture of Mąkowski and Schinzel},
url = {http://eudml.org/doc/210499},
volume = {74},
year = {1997},

AU - Cohen, Graeme
TI - On a conjecture of Mąkowski and Schinzel
JO - Colloquium Mathematicae
PY - 1997
VL - 74
IS - 1
SP - 1
EP - 8
LA - eng
KW - Fermat numbers; sum of divisors function; Euler's function
UR - http://eudml.org/doc/210499
ER -


  1. [1] U. Balakrishnan, Some remarks on σ(ϕ(n)), Fibonacci Quart. 32 (1994), 293-296. 
  2. [2] M. Filaseta, S. W. Graham and C. Nicol, On the composition of σ(n) and ϕ(n), unpublished; S. W. Graham, M. Filaseta and C. Nicol, On σϕ(n) (Preliminary Report), Abstracts Amer. Math. Soc. 13.4 (1992), 357. 
  3. [3] R. K. Guy, Unsolved Problems in Number Theory, 2nd ed., Springer, New York, 1994. Zbl0805.11001
  4. [4] G. H. Hardy, A Course of Pure Mathematics, Cambridge Univ. Press, 1960. 
  5. [5] A. Mąkowski and A. Schinzel, On the functions ϕ(n) and σ(n), Colloq. Math. 13 (1964/65), 95-99. 
  6. [6] C. Pomerance, On the composition of the arithmetic functions σ and ϕ, ibid. 58 (1989), 11-15. 

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