Collatz Conjecture (3n+1)

The Collatz conjecture (the 3n+1 problem) starts with any whole number and applies one simple rule over and over: if the number is even, divide it by 2, and if it is odd, multiply it by 3 and add 1. The conjecture says every starting number eventually reaches 1.

Example: 6 → 3 → 10 → 5 → 16 → 8 → 4 → 2 → 1, so 6 reaches 1 in 8 steps. The values rise and fall like hailstones, which is why the path is called a hailstone sequence.