mersenneforum.org - View Single Post

paulunderwood · 2014-02-03, 04:49

Why did I choose 10^360360-10^k-1?

360360 = 2*2*2*3*3*5*7*11*13

For small primes p, 10^((p-1)*a)==1 (mod p), and so 10^360360-10^k-1 is not divisible by p. Consequently, after sieving, there is about 15% of the range left and we expect to find about 3 primes in the provable range k=90090-360360.

2014-02-03, 04:49	#1
paulunderwood Sep 2002 Database er0rr 2⁴·7·37 Posts	Why NeRDs_360360? Why did I choose 10^360360-10^k-1? 360360 = 22233571113 For small primes p, 10^((p-1)*a)==1 (mod p), and so 10^360360-10^k-1 is not divisible by p. Consequently, after sieving, there is about 15% of the range left and we expect to find about 3 primes in the provable range k=90090-360360.