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 A351682 #30 May 05 2023 01:43:17 %S A351682 2,3,11,13,17,19,29,31,47,53,71,103,113,127,131,137,139,149,173,179, %T A351682 181,191,211,233,239,241,251,257,263,269,293,317,347,367,379,401,431, %U A351682 439,449,461,503,509,523,541,557,587,607,617,619,647,653,683,691,733,743,761,773,797,821,823,827,853,859,881,919,929 %N A351682 Prime numbers p such that the (p-1)-st Bell number B(p-1) is a primitive root modulo p. %C A351682 Heuristically, the density of the sequence in the primes should approach Artin's constant: 0.3739558136... %H A351682 Robert Israel, <a href="/A351682/b351682.txt">Table of n, a(n) for n = 1..500</a> %e A351682 For n = 2 one has a(2) = 3 since B(2) = 2 is a primitive root modulo 3. %p A351682 filter:= proc(p) local b; %p A351682 b:= combinat:-bell(p-1); %p A351682 numtheory:-order(b,p) = p-1 %p A351682 end proc: %p A351682 select(filter, [seq(ithprime(i),i=1..200)]); # _Robert Israel_, May 04 2023 %Y A351682 Cf. A000110, A005596, A350429. %K A351682 nonn %O A351682 1,1 %A A351682 _Luis H. Gallardo_, May 04 2022 %E A351682 Corrected by _Robert Israel_, May 04 2023