Goldbach's weak conjecture

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Call an integer pp prime if p>1p>1 and its only positive divisors are 11 and pp; the primes in a representation are not required to be distinct.

For every odd integer n>5n>5 there exist primes p,q,rp,q,r with

n=p+q+r.n=p+q+r.

Moreover, for every odd integer n>7n>7 there exist odd primes p,q,rp,q,r with

n=p+q+r,n=p+q+r,

so that no summand equals 22.

Equivalent formulations 1Other wordings

Other statements of this same problem, merged from separate entries. Each is equivalent to the statement above — proving any one settles them all.

  1. Goldbach's weak conjecture

    In number theory, Goldbach's weak conjecture, also known as the odd Goldbach conjecture, the ternary Goldbach problem, or the 3-primes problem, is the proposition that every odd number greater than 5 can be expressed as the sum of three primes.

    source: Wikipedia

References

Primary source

Wikipedia

Additional references

  1. Wikipedia, Goldbach's weak conjecture, the article this problem comes from.

Progress summary

Refreshed
Claimed solved

Harald Helfgott proved the conjecture, and later mathematical sources treat the proof as established rather than an unresolved claim.

The problem asserts that every odd integer above 55 is a sum of three primes, with the stronger odd-prime version for integers above 77. Harald Helfgott announced the complete proof in 20132013; later sources distinguish this settled ternary statement from the still-open strong Goldbach conjecture.

Known results

  • Vinogradov proved the assertion for sufficiently large odd integers; later estimates gave a threshold near 10134610^{1346}.
  • Yannick Saouter checked the conjecture computationally through 102010^{20}.
  • Terence Tao proved that every odd integer is a sum of at most five primes, in 20122012.
  • Helfgott reduced the analytic threshold to roughly 102710^{27}-103010^{30}, with David Platt verifying the finite remainder.

2013-2015 proof and subsequent confirmation

Helfgott’s proof combined explicit circle-method estimates with computation and established the full range. It was accepted for the Annals of Mathematics Studies book series in 20152015; later papers state the theorem as proved, and a 20242024 paper develops a restricted-prime extension rather than challenging the original result.

Current status (as of August 2026): The weak Goldbach conjecture, including the odd-prime formulation for odd integers above 77, is resolved; the strong Goldbach conjecture remains open.

Sources

Solutions 0

No solutions have been posted yet.