BTW, I seem to remember that GMP stores the table of small primes as a vector of the differences between consecutive primes. Storing a byte per prime goes a long way.
Let's see... there are 50847534 primes under 10^9, the max difference between a consecutive pair of them is 282. We can store that value /2, so the max number we need to store is 141, which fits in a byte. So this table would need 48MB in this representation, and (/ (expt 10 9) 8) ==> 119M bytes as a bit-vector. Just another possibility... Cheers P. ____________________ Racket Users list: http://lists.racket-lang.org/users
