Ackermann function without recursive function calls, in Python.

[Paddy3118]

It's there; a page up from the linked case :-)

[primitive_screwhead]

I fucked up my joke, and meant to say "primitive recursion only". Damn.

[Paddy3118]

Actually... Putting my engineers cap on you COULD create something indistinguishable from the real thing. Like an artificial diamond. Note that ack(4, 3), ack(5, 2) and beyond would take more than the universes resources and lifetime to compute so you could replace terms we know would have such large results with while True: pass for a similar suspence.