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 A128668 #23 Apr 22 2025 12:20:34 %S A128668 2,3,46021,48947,478225523351 %N A128668 Primes p such that p^2 divides 17^(p-1) - 1. %C A128668 Mossinghoff showed that there are no further terms up to 10^14. %D A128668 Paulo Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004. See p. 233. %H A128668 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 A128668 Richard Fischer, <a href="http://www.fermatquotient.com/FermatQuotienten/">Fermat quotients B^(P-1) == 1 (mod P^2)</a> %H A128668 M. J. Mossinghoff, <a href="http://academics.davidson.edu/math/mossinghoff/WiefPairsBarkerSeqs_MJM.pdf">Wieferich pairs and Barker sequences</a>, Des. Codes Cryptogr. 53 (2009), 149-163. %t A128668 Select[Prime[Range[5*10^6]], Mod[ 17^(# - 1) - 1, #^2] == 0 &] (* _G. C. Greubel_, Jan 18 2018 *) %Y A128668 Cf. A001220, A014127, A123692, A123693, A128667, A090968, A128669, A039951. %K A128668 hard,more,nonn %O A128668 1,1 %A A128668 _Alexander Adamchuk_, Mar 26 2007 %E A128668 The prime 478225523351 was found by Richard Fischer on Oct 25 2005 %E A128668 Extension corrected by _Jonathan Sondow_, Jun 24 2010