This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A377176 #8 Oct 23 2024 20:26:52 %S A377176 3,17,19,23,29,37,41,59,73,79,83,89,109,127,139,149,191,197,227,239, %T A377176 251,257,263,277,283,307,313,317,353,359,373,389,409,419,431,433,467, %U A377176 487,521,523,541,557,563,577,587,593,599,601,619,643,653,691,701,761,769,821,857,863,919,929,937,967,991 %N A377176 Primes p such that 7/2 is a primitive root modulo p. %C A377176 If p is a term in this sequence, then 7/2 is not a square modulo p (i.e., p is in A038886). %C A377176 Conjecture: this sequence has relative density equal to Artin's constant (A005596) with respect to the set of primes. %H A377176 Wikipedia, <a href="https://en.wikipedia.org/wiki/Artin%27s_conjecture_on_primitive_roots">Artin's conjecture on primitive roots</a>. %H A377176 <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a> %o A377176 (PARI) print1(3, ", "); forprime(p=11, 10^3, if(znorder(Mod(-5/2, p))==p-1, print1(p, ", "))); %Y A377176 Primes p such that +a/2 is a primitive root modulo p: A320384 (a=3), A377174 (a=5), this sequence (a=7), A377178 (a=9). %Y A377176 Primes p such that -a/2 is a primitive root modulo p: A377172 (a=3), A377175 (a=5), A377177 (a=7), A377179 (a=9). %Y A377176 Cf. A038886, A005596. %K A377176 nonn,easy %O A377176 1,1 %A A377176 _Jianing Song_, Oct 18 2024