PPL 050 / 177 permanent IDsPrize Problem Ledger · PPLChecked 2026.07.26
Prize Problem LedgerErdősPPL 050Erdős Problem #241

Permanent problem IDPPL 050

Verified openErdősconjecture

Additive combinatorics

Erdős Problem #241

Let f(N) be the maximum size of A⊆ {1,…,N} such that the sums a+b+c with a,b,c∈ A are all distinct (aside from the trivial coincidences). Is it true that f(N)\sim N^(1/3)?

additive combinatoricssidon sets
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The problem

Let f(N) be the maximum size of A⊆ {1,…,N} such that the sums a+b+c with a,b,c∈ A are all distinct (aside from the trivial coincidences). Is it true that f(N)\sim N^(1/3)?

Open since1962source estimate
Last checked2026.07.26Catalog verification
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Reward offers

Offer 01$100Paul 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