A081764 Primes p such that p*(p-2) divides 3^(p-1)-1.

37, 457, 1297, 2557, 4357, 6481, 8689, 11953, 14401, 26497, 33931, 44101, 47521, 47881, 90631, 141157, 157081, 165601, 206221, 225457, 304081, 366097, 384049, 427351, 446881, 560737, 576721, 589591, 636781, 677041, 1037857, 1046641, 1049941, 1079569

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..100 from Harvey P. Dale)

Mathematica

Select[Prime[Range[85000]], PowerMod[3, #-1, #(#-2)]==1&]//Quiet (* Harvey P. Dale, Mar 19 2019 *)

Prog

(PARI) lista(nn) = {forprime(p=3, nn, if (! ((3^(p-1)-1) % (p*(p-2))), print1(p, ", ")); ); }
(PARI) isok(p) = p > 2 && isprime(p) && Mod(3, p*(p-2))^(p-1) == 1; \\ Amiram Eldar, May 01 2025

Crossrefs

Sequence in context: A227825 A201609 A140847 * A142567 A142286 A166132

Adjacent sequences: A081761 A081762 A081763 * A081765 A081766 A081767

Keyword

nonn

Author

Benoit Cloitre, Apr 09 2003

Extensions

More terms from Michel Marcus, Dec 02 2013

Status

approved