A seemingly simple set of rules kicks off a kind of mathematical magic trick, which has kept great minds busy since the 1930s ...

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 ...

Mathematicians regard the Collatz conjecture as a quagmire and warn each other to stay away. But now Terence Tao has made more progress than anyone in decades. Experienced mathematicians warn ...

Some years ago, I wrote here about “hailstone numbers” (Follow that hailstone, 8 April 2016). These are numbers that are generated when you try your hand at the Collatz Conjecture—sometimes described ...