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A212583 Primes p such that p^2 divides 6^(p-1) - 1. 7
66161, 534851, 3152573 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Base 6 Wieferich primes.

Next term > 4.119*10^13. [See Fischer link]

REFERENCES

P. Ribenboim, The New Book of Prime Number Records, Springer-Verlag, 1996, page 347

LINKS

Table of n, a(n) for n=1..3.

François G. Dorais and Dominic Klyve, A Wieferich prime search up to p < 6.7*10^15, J. Integer Seq. 14 (2011), Art. 11.9.2, 1-14.

Richard Fischer, Thema: Fermatquotient B^P-1 == 1 mod (P^2)

Wilfrid Keller and Jörg Richstein, Fermat quotients q_p(a) that are divisible by p.

Eric Weisstein, Fermat Quotient, MathWorld

Wikipedia, Base-a Wieferich primes

PROG

(PARI)

N=10^9; default(primelimit, N);

forprime(n=2, N, if(Mod(6, n^2)^(n-1)==1, print1(n, ", ")));

\\ Joerg Arndt, May 01 2013

CROSSREFS

Cf. A001220, A014127, A090968, A123692, A123693, A128667, A128668, A128669.

Sequence in context: A254185 A253797 A241978 * A156424 A092376 A251333

Adjacent sequences:  A212580 A212581 A212582 * A212584 A212585 A212586

KEYWORD

nonn,hard,bref,more

AUTHOR

Felix Fröhlich, May 22 2012

STATUS

approved

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Last modified December 4 19:20 EST 2016. Contains 278755 sequences.