Hailstone, also known as the Collatz sequence, is a mathematical sequence generated by following a specific set of rules. The sequence starts with a positive integer. If the number is even, it is divided by 2. If the number is odd, it is multiplied by 3 and then 1 is added to the result. This process is repeated for each subsequent number in the sequence until eventually reaching the number 1. The sequence is called hailstone due to the repetitive nature of numbers rising and falling, similar to the way hailstones fall and bounce.
