4 ms·
919444^1048576+1 (new Generalized Fermat mega prime)
- timonoko 9y agoIs this one of those primes that are all 1's in binary?
- gus_massa 9y agoNo, but it's a relevant question anyway. Mersenne prime: 2^n-1, for example 31=11111[base 2], we know 49 of them Fermat prime: 2^(2^n)+1: for example 17=10001[base 2], we know 5 of them] This is similar to a Fermat prime, but it's not exactly a Fermat prime. So the binary representation is horrible. The main idea is that is you know the prime factorization of N+1 or N-1, then it's helpful to test if N is prime or not.