Work out collatz sequence instantly with clear inputs, formula shown and shareable results.
The Collatz rule halves even numbers and maps odd n to 3n + 1. Every tested starting value eventually reaches 1, but no proof exists — this is the Collatz conjecture.
Collatz step
n → n/2 if n is even, otherwise n → 3n + 1
111 steps, peaking at 9232 — famously long for such a small start.
No. It has been verified past 2⁶⁸ by computer but remains open, and Erdős remarked mathematics is not ready for such problems.