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 A019350 #18 Jan 09 2024 10:58:52
%S A019350 2,3,5,17,47,59,89,97,113,127,131,137,149,167,179,181,223,229,281,293,
%T A019350 307,311,337,347,389,401,421,433,439,443,457,487,491,499,521,547,557,
%U A019350 569,587,599,607,617,641,647,661,677,683,709,719,733,739,769,773,797,811,823
%N A019350 Primes with primitive root 23.
%H A019350 Vincenzo Librandi, <a href="/A019350/b019350.txt">Table of n, a(n) for n = 1..1000</a>
%H A019350 <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a>
%t A019350 pr=23; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
%t A019350 Join[{2,3,5,17},Select[Prime[Range[200]],PrimitiveRoot[#,23]==23&]] (* _Harvey P. Dale_, Jan 09 2024 *)
%o A019350 (PARI) is(n)=isprime(n) && n!=23 && znorder(Mod(23,n))==n-1 \\ _Charles R Greathouse IV_, Sep 28 2015
%K A019350 nonn
%O A019350 1,1
%A A019350 _David W. Wilson_