Did you really mean 2^45 (47) or 2**45 (35184372088832).

A double-precision floating point number can handle numbers much bigger than 2**45. And with 53 bits of precision, it can represent 2**45 faithfully.

If so, how can I go about fixing this?

See the "64 bit support" section in the perl distribution's INSTALL file for how to build such a perl.

Or like I said already, tell me which cell of my table you want, and I'll provide some code to do the same thing on a 32-bit build of Perl.