What evidence is there that 2^65536 is a natural number?
David J. Isles · Notre Dame Journal of Formal Logic · 1992
The closure of the natural numbers under exponentiation a A b is a fact which is central to results in metamathematics.The argument which purports to establish this closure involves a simple mathematical induction.An analysis of this proof shows that it may involve a new and subtle form of circularity.