PPL 042 / 177 permanent IDsPrize Problem Ledger · PPLChecked 2026.07.26
Prize Problem LedgerErdősPPL 042Erdős Problem #138

Permanent problem IDPPL 042

Verified openErdősconjecture

Additive combinatorics

Erdős Problem #138

Let the van der Waerden number W(k) be such that whenever N≥ W(k) and {1,…,N} is 2-coloured there must exist a monochromatic k-term arithmetic progression. Improve the bounds for W(k) - for example, prove that W(k)^(1/k)→ ∈fty.

additive combinatorics
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The problem

Let the van der Waerden number W(k) be such that whenever N≥ W(k) and {1,…,N} is 2-coloured there must exist a monochromatic k-term arithmetic progression. Improve the bounds for W(k) - for example, prove that W(k)^(1/k)→ ∈fty.

Open since1957earliest source
Last checked2026.07.26Catalog verification
02

Reward offers

Offer 01$500Paul Erdős / Combinatorics Foundation
Documented

A solution must appear in a reputable journal, with documentation that Erdős offered the displayed amount. Claims are administered by the Combinatorics Foundation; erdosproblems.com does not pay awards.

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Sources & reading