The iteration (or sequence):
n is a positive integer 0.5n if n is even 3n + 1 if n is odd
Wow plots! These were generated by preforming the sequence on a large set of numbers and recording the number of iterations it took to reach 1.
What's cool is that this sequence is easy to parallelize. Boom, lets use a GPU. The code was written using the native Rust implementation of WebGPU: wgpu.
Read more on Wikipedia.