Any two 200 digit primes will do it, but your isa_prime() and gen_primes() subs are way too inefficient to find primes of that size. You are hoping to test primality by exhaustively checking every number less than the candidate as a divisor. That will take more than 10**200 divisions. If you can do one every 10 nanoseconds, that gives you 10**192 seconds, or around 10**175 ages of the universe to check a single number.

Has your math professor given you some reading on the subject of primality testing? If not, check The Prime Pages.

Math::Pari is very good for number theory kind of things.

After Compline,
Zaxo

In reply to Re: Finding Primes by Zaxo
in thread Finding Primes by Tommy

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