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 A294722 #22 Jul 29 2023 23:14:57
%S A294722 5,31,167,100511
%N A294722 Numbers k such that (44^k - 1)/43 is prime.
%C A294722 The number corresponding to a(4) is a probable prime.
%C A294722 These are the indices of base-44 repunit primes, i.e., numbers k such that A002275(k) interpreted as a base-44 number and converted to decimal is prime. - _Felix Fröhlich_, Nov 08 2017
%H A294722 P. Bourdelais, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;417ab0d6.0906">A generalized repunit conjecture</a>
%t A294722 ParallelMap[ If[ PrimeQ[(44^# - 1)/43], #, Nothing] &, Prime@Range @ 10000] (* _Robert G. Wilson v_, Nov 25 2017 *)
%o A294722 (PFGW) ABC2 (44^$a-1)/43 // -f{2*$a}
%o A294722 a: primes from 2 to 1000000
%o A294722 (PARI) is(n) = ispseudoprime((44^n-1)/43) \\ _Felix Fröhlich_, Nov 08 2017
%Y A294722 Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035, A127995, A127996, A127997, A127998, A127999, A098438, A128002, A128003, A128004, A128005, A240765.
%K A294722 nonn,more
%O A294722 1,1
%A A294722 _Paul Bourdelais_, Nov 07 2017