View Single Post
 2020-09-08, 06:41 #370 kar_bon     Mar 2006 Germany 22×23×31 Posts 1281979*2^n-1 has a Nash weight of 1789, so relatively low. 1281979 $\equiv$ 1 mod 3 so all primes of that sequence are only odd n-values. k-values with 2 mod 3 can only produce primes with even n's, and k's divisible by 3 can produce primes with odd/even n-values. 1281979*2^n+1 has a low Nash weight of 847, so there should less primes for this sequence. The Liskovets-Gallot conjectures study the contribution of odd/even n-values of such seqs. There exits k-values which never produce primes for any n-value like the Riesel problem. PS: If your're done you can list the prime n-values in this thread and I can include those in the Wiki, both sides (Proth /Riesel) possible. Don't forget to give the search limits then. Last fiddled with by kar_bon on 2020-09-08 at 06:47 Reason: PS