Day 210 #432

Good morning! Here's your coding interview problem for today.

This problem was asked by Apple.

A Collatz sequence in mathematics can be defined as follows. Starting with any positive integer:

if n is even, the next number in the sequence is n / 2
if n is odd, the next number in the sequence is 3n + 1
It is conjectured that every such sequence eventually reaches the number 1. Test this conjecture.

Bonus: What input n <= 1000000 gives the longest sequence?