login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A081764 Primes p such that p*(p-2) divides 3^(p-1)-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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..100

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, ", ")); ); }

CROSSREFS

Sequence in context: A227825 A201609 A140847 * A142567 A142286 A166132

Adjacent sequences:  A081761 A081762 A081763 * A081765 A081766 A081767

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Apr 09 2003

EXTENSIONS

More terms from Michel Marcus, Dec 02 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 14 05:08 EDT 2019. Contains 327995 sequences. (Running on oeis4.)