Or the inverse TREE() function [1]. There's also the inverse Busy Beaver functio...

		tromp on Dec 13, 2019 \| parent \| context \| favorite \| on: Terence Tao Proves Result on the Collatz Conjectur... Or the inverse TREE() function [1]. There's also the inverse Busy Beaver function if you don't insist on computability... [1] https://en.wikipedia.org/wiki/Kruskal%27s_tree_theorem#TREE(...