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 A348170 #19 Sep 22 2022 01:40:12
%S A348170 313,1297,568453
%N A348170 Numbers k such that (35^k - 1)/34 is prime.
%C A348170 These are the repunit primes in base 35.
%H A348170 Paul Bourdelais, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;417ab0d6.0906">A Generalized Repunit Conjecture</a>
%e A348170 313 is a term since (35^313 - 1)/34 is a prime. It has 482 digits in base 10.
%t A348170 Do[ If[ PrimeQ[ (35^n-1)/34], Print[n]], {n, 0, 600000}]
%o A348170 (PARI) is(n)=isprime((35^n-1)/34)
%Y A348170 Cf. A309533, A309532, A237052, A229145, A057191, A057182, A057175.
%Y A348170 Cf. A218738.
%K A348170 nonn,bref,hard,more
%O A348170 1,1
%A A348170 _Paul Bourdelais_, Oct 04 2021