A280150 Primes p such that 68^(p-1) == 1 (mod p^2).

5, 7, 19, 113, 2741

Offset

1,1

Comments

For p = 5 and 113 is 68^(p-1) == 1 (mod p^3).

No further terms up to 7.74*10^13 (cf. Fischer link). - Felix Fröhlich, Dec 27 2016

Links

Table of n, a(n) for n=1..5.

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

Mathematica

Select[Prime[Range[500]], PowerMod[68, #-1, #^2]==1&] (* Harvey P. Dale, Aug 07 2019 *)

Prog

(PARI) forprime(p=1, , if(Mod(68, p^2)^(p-1)==1, print1(p, ", "))) \\ Felix Fröhlich, Dec 27 2016

Crossrefs

Cf. A001220, A273085.

Sequence in context: A096636 A101588 A288405 * A062654 A231865 A130729

Adjacent sequences: A280147 A280148 A280149 * A280151 A280152 A280153

Keyword

nonn,more

Author

Thomas Ordowski, Dec 27 2016

Extensions

a(5) from Felix Fröhlich, Dec 27 2016

Status

approved