Source: /cirosantilli/collatz-conjecture

= Collatz conjecture
{c}
{tag=Simple to state but hard to prove}
{title2=1937-}
{wiki}

Given stuff like https://arxiv.org/pdf/2107.12475.pdf on <Erdős' conjecture on powers of 2>, it feels like this one will be somewhere close to <computer science>/<Halting problem> issues than <number theory>. Who knows. This is suggested e.g. at <The Busy Beaver Competition: a historical survey by Pascal Michel>.