mersenneforum.org - View Single Post - Efficient storage of all primes up to some n

hansl · 2019-05-09, 22:34

Another idea would be to create a large sieve bitfield, where each 1 bit represents a prime.
By once again ignoring the only even prime 2, we could cut the bitfield in half
2^32/8/1024/1024/2 = 256 MiB

Simple, but not as effective as the prime gap idea.

2019-05-09, 22:34	#2
hansl Apr 2019 5×41 Posts	Another idea would be to create a large sieve bitfield, where each 1 bit represents a prime. By once again ignoring the only even prime 2, we could cut the bitfield in half 2^32/8/1024/1024/2 = 256 MiB Simple, but not as effective as the prime gap idea.