login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A125556 Smallest prime p = n*m + 1 that divides m^m - 1 for some m > 1. 2
3, 11, 61, 13, 31, 241, 43, 257, 271, 251, 1013, 673, 157, 71, 541, 241, 307, 883, 4409, 401, 1471, 463, 5843, 577, 601, 2081, 271, 757, 1973, 241, 2729, 2657, 4951, 1123, 21701, 937, 32191, 14479, 3433, 641, 1723, 2521, 5849, 6689, 1531, 6257, 18143 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Corresponding numbers m > 1 such that a(n) divides m^m - 1 are m = (a(n) - 1)/n = {2,5,20,3,6,40,6,32,30,25,92,56,12,5,36,15,18,...}.

LINKS

Joseph L. Wetherell, Table of n, a(n) for n = 1..10000

PROG

(PARI) a(n) = forprime(p=3, , if (!((p-1) % n) && (m = (p-1)/n) && (m > 1) && !((m^m-1) % p), return (p)); ); \\ Michel Marcus, Nov 18 2017

CROSSREFS

Cf. A048861 (n^n - 1).

Sequence in context: A231344 A007146 A076475 * A127516 A228204 A095237

Adjacent sequences:  A125553 A125554 A125555 * A125557 A125558 A125559

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Jan 22 2007

EXTENSIONS

Corrected a(47) and extended by Alexander Adamchuk, May 09 2010

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 February 25 19:39 EST 2021. Contains 341618 sequences. (Running on oeis4.)