Abusing the Unlimited time limit
Because of the fact that Repl doesn't have a time limit on the projects, I could theoretically find the world's largest prime number in a couple of hours.
Cool Animations though
Why did I decide to see this WHILE I have a headache?
Really cool though!
Also, i know that this may crash your repl due to overflow on the variable, but you could do an infinite for loop with:
Just a thought!