01
The problem
Let R_3(n) be the minimal m such that if the edges of the 3-uniform hypergraph on m vertices are 2-coloured then there is a monochromatic copy of the complete 3-uniform hypergraph on n vertices. Is there some constant c>0 such that R_3(n) ≥ 2^{2^(cn)}?
Open since1965exact
Last checked2026.07.26Catalog verification
02
Reward offers
Offer 01$500Paul 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.