Erdős Problem 592

Reference: erdosproblems.com/592

theorem erdos_592 (β : Ordinal.{u}) : β.card ≤ Cardinal.aleph0 → OmegaPowerRamsey β 3 ↔ sorry β

Determine which countable ordinals $β$ have the property that, if $α = \omega^β$, then in any red/blue colouring of the edges of $K_α$ there is either a red $K_α$ or a blue $K_3$.