I very much enjoyed determining functional busy beaver numbers [1]. Maybe somewhere in between the enjoyment from the computable numbers of Go and chess. There

I very much enjoyed determining functional busy beaver numbers [1]. Maybe somewhere in between the enjoyment from the computable numbers of Go and chess. There is no estimation involved there. Although there are lower bounds. The other difference being that it's a much more esoteric subject (on account of the prevalence of the Turing Machine based definition) with a much more limited audience. [1] https://oeis.org/A333479 https://oeis.org/A333479