User blog comment:MilkyWay90/Yet another attempt at making a fast-growing function/@comment-35434595-20180709002245/@comment-30754445-20180709003945

I suppose he meant "largest number definable in Peano arithmetic with n symbols".

Which has the potential of being a very fast growing function (in fact, it would outgrow any computable function). Unfortunately, this would not be well-defined either, unless we specify the exact language we're using to describe Peano arithmetic (and the precise method we use to count the symbols).

Also, once all the technicalities are taken care of, this function would be nothing more than a minor variation of Rayo's function. Just repeating what someone else already did, is kind-of missing the point of doing googology.