Good point. We’re still not describing it perfectly. Admittedly I’m doing it by my memory of the last time I read Wolframs ideas. I think we unfortunately have to describe it using Kolmogorov complexity: what is the length of the shortest computer program that produces the object as an output? What Wolfram means by computational irreducibility is that he asserts that reality itself is the shortest length computer program that can produce its own output, and it can’t be shortened (reduced) any further without losing information.

Edit: sorry I think I still haven’t fully described it. Will have to come back to it tomorrow when I’ve had some sleep

Actually there’s an explicit formula for Finonacci(x) that involves phi. I think you can use generating functions to derive it.

(But your overall point still stands.)