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 A248865 #46 Sep 08 2020 02:16:54 %S A248865 2,11,269,487,653,1093,3511,1006003 %N A248865 Primes p that set a new record for the number of bases 1 < b < p for which p is a base-b Wieferich prime. %C A248865 Primes p where A242830(i) reaches record values, where i is the index of p in A000040. %C A248865 The corresponding number of bases are 0, 2, 3, 4, 5, 10, 11, 12. - _Jianing Song_, Feb 07 2019 %C A248865 From _Jeppe Stig Nielsen_, Sep 06 2020: (Start) %C A248865 Note that for a(6) and a(7), all the b values (bases) that are counted are powers of 2; and for a(8) all are powers of 3. %C A248865 See A334048 for a version where bases b that are powers are not allowed. %C A248865 One candidate for a(9) is 1645333507; it has 14 bases, the first 13 of which are powers of 5. However, excluding all numbers under 1645333507 as candidates for a(9) may be difficult to do. %C A248865 (End) %o A248865 (PARI) my(r=-1); forprime(p=2, , my(b=2, i=0); while(b < p, if(Mod(b, p^2)^(p-1)==1, i++); b++); if(i > r, print1(p, ", "); r=i)) \\ changed to include a(1) = 2 by _Jianing Song_, Feb 07 2019 %Y A248865 Cf. A000040, A175932, A242830, A334048. %Y A248865 Subsequence of A175932. Apart from the first term, subsequence of A134307. %K A248865 nonn,hard,more %O A248865 1,1 %A A248865 _Felix Fröhlich_, Mar 07 2015 %E A248865 a(1) = 2 inserted by _Jianing Song_, Feb 07 2019