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The Weak Goldbach Conjecture (ternary)

historic

Posed by Christian Goldbach · 1742 · number theory · resolved 13 May 2013 · ~1 min read · difficulty 4/5

The problem

Every odd integer \(n > 5\) is the sum of three odd primes (repetitions allowed), e.g. \(7 = 2+2+3\). Vinogradov (1937) proved it for all sufficiently large odds; Helfgott (2013) closed the remaining range, completing the proof.

History & significance

Implicit in the 1742 Goldbach–Euler correspondence. Vinogradov (1937) removed reliance on GRH for all sufficiently large odds, but "sufficiently large" meant astronomically beyond reach; explicit bounds descended from e^{e^{\(e^{41}\)}} toward computability over decades (Liu–Wang reached \(e^{3100}\)).