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 A212583 #38 Feb 16 2025 08:33:17 %S A212583 66161,534851,3152573 %N A212583 Primes p such that p^2 divides 6^(p-1) - 1. %C A212583 Base 6 Wieferich primes. %C A212583 Next term > 4.119*10^13. [See Fischer link] %D A212583 P. Ribenboim, The New Book of Prime Number Records, Springer-Verlag, 1996, page 347 %H A212583 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 p. 5. %H A212583 François G. Dorais and Dominic 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 A212583 Richard Fischer, <a href="http://www.fermatquotient.com/FermatQuotienten/FermQ_Sort">Thema: Fermatquotient B^P-1 == 1 mod (P^2)</a> %H A212583 Wilfrid Keller and Jörg Richstein, <a href="http://www1.uni-hamburg.de/RRZ/W.Keller/FermatQuotient.html">Fermat quotients q_p(a) that are divisible by p</a>. %H A212583 Eric Weisstein, <a href="https://mathworld.wolfram.com/FermatQuotient.html">Fermat Quotient</a>, MathWorld %H A212583 Wikipedia, <a href="http://en.wikipedia.org/wiki/Wieferich_prime#Base-a_Wieferich_primes">Base-a Wieferich primes</a> %t A212583 Select[Prime[Range[1000000]], PowerMod[6, # - 1, #^2] == 1 &] (* _Robert Price_, May 17 2019 *) %o A212583 (PARI) %o A212583 N=10^9; default(primelimit,N); %o A212583 forprime(n=2,N,if(Mod(6,n^2)^(n-1)==1,print1(n,", "))); %o A212583 \\ _Joerg Arndt_, May 01 2013 %Y A212583 Cf. A001220, A014127, A090968, A123692, A123693, A128667, A128668, A128669. %K A212583 nonn,hard,bref,more %O A212583 1,1 %A A212583 _Felix Fröhlich_, May 22 2012