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Conjecture

Fortune's Conjecture

Number Theory

Fortune's conjecture, named for Reo Fortune, states that no Fortunate number is composite. A Fortunate number is defined, for a given positive integer n, as the smallest integer m greater than 1 such that the sum of the primorial of the first n primes and m is itself prime. As of 2017 every known Fortunate number was prime, verified up to n equal to 3000, but the conjecture that this holds for every Fortunate number remains unproven.

Facts
Statement
For a positive integer n, a Fortunate number is defined as the smallest integer m greater than 1 such that the sum of the primorial of the first n primes and m is prime. Fortune's conjecture states that no Fortunate number is composite, meaning every Fortunate number is itself prime. 1
Progress Toward Resolution
As of 2017 the conjecture had been verified computationally with every known Fortunate number found to be prime, checked up to n equal to 3000, but no general proof exists. 1
Classification
Resolution Status
Open 1
Prize Status
Prize Status (category)
No Prize Offered 1
Connections

In Branch

Source Fortunate number (Wikipedia)
Sources
1. Fortune's Conjecture (Wikipedia)
  • Lead section, definition
    Fortune conjectured that no Fortunate number is composite.
  • Lead section, verification status
    all known Fortunate numbers are prime, checked up to n = 3000
  • Lead section
View the Source
Fortunate number (Wikipedia)
In Branch: Number Theory, Lead sentenceView the Source
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