

A248865


Primes p that set a new record for the number of bases 1 < b < p for which p is a baseb Wieferich prime.


4




OFFSET

1,1


COMMENTS

Primes p where A242830(i) reaches record values, where i is the index of p in A000040.
The corresponding number of bases are 0, 2, 3, 4, 5, 10, 11, 12.  Jianing Song, Feb 07 2019


LINKS

Table of n, a(n) for n=1..8.


PROG

(PARI) my(r=1); forprime(p=2, , my(b=2, i=0); while(b < p, if(Mod(b, p^2)^(p1)==1, i++); b++); if(i > r, print1(p, ", "); r=i)) \\ changed to include a(1) = 2 by Jianing Song, Feb 07 2019


CROSSREFS

Cf. A000040, A175932, A242830.
Subsequence of A175932. Apart from the first term, subsequence of A134307.
Sequence in context: A134096 A132571 A102031 * A072386 A185122 A198894
Adjacent sequences: A248862 A248863 A248864 * A248866 A248867 A248868


KEYWORD

nonn,hard,more


AUTHOR

Felix FrÃ¶hlich, Mar 07 2015


EXTENSIONS

a(1) = 2 inserted by Jianing Song, Feb 07 2019


STATUS

approved



