Mathematics Atlas

How Proof Is Made
Sign In
Text size
100%
Theme
Conjecture

Erdos-Straus Conjecture

AIR-dosh strows kon-JEK-cher (Paul Erdos, Ernst G. Straus)
Number Theory

The Erdos-Straus conjecture is an unproven number theory statement asserting that for every integer n greater than or equal to 2, the fraction 4/n can be expressed as a sum of three positive unit fractions. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/

Facts
Statement
For every integer n greater than or equal to 2, there exist positive integers x, y and z such that 4/n = 1/x + 1/y + 1/z. 1
Proposed Year
1948 1
Prize Status
Not a Millennium Prize Problem; no major institutional prize is attached, though it has attracted sustained attention from number theorists since 1948. 1
Progress Toward Resolution
Computer searches have verified the conjecture for every n up to 10^17. Modular identities supply solutions for infinitely many arithmetic progressions of n, and the natural density of potential counterexamples has been shown to be zero, though no general proof exists. Allowing negative integers for x, y or z makes the problem trivially solvable, so the difficulty is specific to the positive-integer requirement. 1
Classification
Resolution Status
Open 1
Prize Status
Prize Status (category)
No Prize Offered 1
Connections

In Branch

Additional Source Erdos-Straus Conjecture (Wikipedia)Opening paragraph

Open Questions

Posed By

Source Erdos-Straus Conjecture (Wikipedia)
Source Erdos-Straus Conjecture (Wikipedia)
Sources
1. Erdos-Straus Conjecture (Wikipedia)
Wikipedia
  • Lead and verification sections
    The conjecture is named after Paul Erdos and Ernst G. Straus, who formulated it in 1948, but it is connected to much more ancient mathematics.
  • Statement section
    4/n = 1/x + 1/y + 1/z
  • Lead section
    an unproven statement in number theory
  • Verification and progress sections
    Computer searches have verified the truth of the conjecture up to n <= 10^17
  • History section
    who formulated it in 1948
  • In Branch: Number Theory, Opening paragraph
    The Erdos-Straus conjecture is an unproven statement in number theory.
View the Source
Open Questions (1 open question)
Does the Erdos-Straus equation 4/n = 1/x + 1/y + 1/z really have a positive-integer solution for every integer n of 2 or more?

Computer search has confirmed the equation solvable for every n up to 10^17, and modular identities cover infinitely many residue classes, but no argument closes the remaining, conjecturally empty, set of exceptions for every n at once.

What would resolve this A general proof, or a genuine counterexample, covering every integer n rather than a further extension of the verified range.
Number theoryErdos-Straus Conjecture (Wikipedia)
Comments (0)
No comments yet. Be the first to share a thought.
Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.