Would you like to try and make a larger number than S.C.B. Nisman and I in under 256 characters with the restriction of no infinity and no calling in constants (or else you'd just call in some really big number and +1 it)
> "Any one of these formulas (or any similar one) would attain a different status [i.e. different from being considered useless] if the exact value of the number α ... could be expressed independently of the primes. There seems no likelihood of this, but it cannot be ruled out as entirely impossible."
If there were a fastest function, add $1$ to it. Or add $n$ to it. Also, if you have infinite sequence $f_k$ of functions, each faster than the last, you can get one faster than all of those by doing $n\mapsto f_n(n)$.
The function $n\mapsto{}$"the largest number definable in $\le n$ characters in Python" grows faster than all computable functions, and is uncomputable.