MrCollatz Support

Questions, bug reports, or a number that won't come down

Email support@44consulting.net and include your iPhone or iPad model and iOS version if you're reporting a problem.

How it works

Take any whole number. If it's even, halve it; if it's odd, triple it and add one. Repeat. The Collatz conjecture says every starting number eventually reaches 1. No one has proved it.

Common questions

What does "You may have disproved the Collatz conjecture" mean?
The number didn't reach 1 within the app's step limit. That's extraordinarily unlikely to be a true counterexample, but please send us the starting number shown.

How big can my own number be?
Up to 15 digits. Random numbers can be 30 to 200 digits; set this in Settings.

Does the app collect any data?
No. See the privacy policy.