3 ms·

I think the distinction is that Graham's Number is a "useful" number; i.e. it was used to help answer a problem. As you note, G + 1 is larger than G but G + 1

• ballenf 9y ago
  As the article states, it wasn't actually used in the proof where it's credited. Graham later cited it because it was easier to describe than his actual upper bounds. I'm a big fan of the busy beaver family of problems and the halting problem is particularly interesting. Naturally, the definition of the numbers and thought process used to describe them is orders of magnitude more interesting than the numbers themselves.