01
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
02
Reward offers
Offer 01$100Paul Erdős / Combinatorics Foundation
DocumentedA 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.