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 A123693 #20 May 17 2019 14:42:51 %S A123693 5,491531 %N A123693 Primes p such that p^2 divides 7^(p-1) - 1. %C A123693 Dorais and Klyve proved that there are no further terms up to 9.7*10^14. %H A123693 Amir Akbary and Sahar Siavashi, <a href="http://math.colgate.edu/~integers/s3/s3.Abstract.html">The Largest Known Wieferich Numbers</a>, INTEGERS, 18(2018), A3. See Table 1 p. 5. %H A123693 F. G. Dorais and D. Klyve, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL14/Klyve/klyve3.html">A Wieferich prime search up to p < 6.7*10^15</a>, J. Integer Seq. 14 (2011), Art. 11.9.2, 1-14. %H A123693 W. Keller and J. Richstein, <a href="http://www1.uni-hamburg.de/RRZ/W.Keller/FermatQuotient.html">Fermat quotients q_p(a) that are divisible by p</a>. %t A123693 Select[Prime[Range[1000000]], PowerMod[7, # - 1, #^2] == 1 &] (* _Robert Price_, May 17 2019 *) %Y A123693 Cf. A001220, A014127, A123692, A123693, A128667, A128668, A090968, A039951, A128669 %K A123693 bref,hard,nonn,more %O A123693 1,1 %A A123693 _Max Alekseyev_, Oct 07 2006 %E A123693 Updated by _Max Alekseyev_, Jan 29 2012