Experienced mathematicians warn up-and-comers to stay away from the Collatz conjecture. It’s a siren song, they say: Fall under its trance and you may never do meaningful work again. The Collatz ...

At first glance, the problem seems ridiculously simple. And yet experts have been searching for a solution in vain for decades. According to mathematician Jeffrey Lagarias, number theorist Shizuo ...

This column comes with a warning: Do not try to solve this math problem. You will be tempted. This problem is simply stated, easily understood, and all too inviting. Just pick a number, any number: If ...