20190326, 07:09  #1 
Mar 2018
17·31 Posts 
primes p(n1) dividing the sum 2+3+5+7+...+p(n)
with Pari Gp i found that up to 10^10 there are only two primes 7 and 8263 of this type. infact 2+3+5+7+11=28 divisibile by 7. and 2+3+5+7+...+8269 divisibile by 8263. the heuristic says that there should be infinitely many of these primes but because the heuristic says loglog(n) they should be very rare. could somebody find onother such prime >10^10?

20190326, 09:07  #2 
Mar 2018
17·31 Posts 
https://oeis.org/A078721
7 and 8263 belong to the Oeis sequence https://oeis.org/A078721
2 3 5 7 11 13 they are on the left side of this Tarrtaglia triangle made with primes 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Mersenne Primes p which are in a set of twin primes is finite?  carpetpool  Miscellaneous Math  3  20170810 13:47 
Distribution of Mersenne primes before and after couples of primes found  emily  Math  34  20170716 18:44 
Conjecture about Mersenne primes and nonprimes v2  Mickey1  Miscellaneous Math  1  20130530 12:32 
A conjecture about Mersenne primes and nonprimes  Unregistered  Information & Answers  0  20110131 15:41 
possible primes (real primes & poss.prime products)  troels munkner  Miscellaneous Math  4  20060602 08:35 