Erdős–Szekeres conjecture on convex-position numbers
Prove that for every integer k ≥ 3, g(k) = 2^{k−2} + 1, where g(k) denotes the smallest integer such that any set of g(k) points in the plane in general position (with no three collinear) contains k points in convex position.
References
Erd\H{o}s and Szekeres conjectured that $g(k) = 2{k-2} + 1$ for every $k$, which matches the three known datapoints, and proved this to be a lower bound.
— Automated Symmetric Constructions in Discrete Geometry
(2506.00224 - Subercaseaux et al., 30 May 2025) in Section 1 (Introduction), Erdős–Szekeres paragraph