@SimplyBeautifulArt @amWhy @Deedlit @Wojowu: Here is my entry:
repl.it/Fomr/1. The first block of comments describes what it does. The second block of comments sketches the proof of termination, but I'd be curious to know who can prove it by themselves! Also, can anyone can identify its rate of growth in terms of the initial value of c? And how much do lines 16,17,18 help? It's the best I could come up with to boost the growth rate.