A331427 - OEIS

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A331427

Prime numbers p such that p^2 divides 41^(p-1) - 1.

2, 29, 1025273, 138200401

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..4.

Richard Fischer, Fermatquotienten von 2 bis 1052, Dec 19 2019.

Wikipedia, Wieferich prime

MATHEMATICA

Select[Range[1.1*10^6], PrimeQ[#] && PowerMod[41, # - 1, #^2] == 1 &] (* Amiram Eldar, May 05 2021 *)

PROG

(PARI) forprime(p=2, 1e8, if(Mod(41, p^2)^(p-1)==1, print1(p", ")))

CROSSREFS

Wieferich primes to base b: A001220 (b=2), A014127 (b=3), A123692 (b=5), A123693 (b=7), A128667 (b=13), A128668 (b=17), A090968 (b=19), A128669 (b=23), A331424 (b=31), A331426 (b=37), this sequence (b=41).

Cf. A039951.

Sequence in context: A180128 A367871 A087194 * A058988 A292879 A361027

Adjacent sequences: A331424 A331425 A331426 * A331428 A331429 A331430

KEYWORD

nonn,more

AUTHOR

Seiichi Manyama, Jan 16 2020

STATUS

approved