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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A128125 Numbers n such that 2^n == 14 (mod n). 7
1, 2, 3, 10, 1010, 61610, 469730, 2037190, 3820821, 9227438, 21728810, 24372562, 207034456857, 1957657325241, 2002159320610, 35169368880130, 36496347203230, 116800477091426 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

No other terms below 10^15. Some larger terms: 279283702428813463, 3075304070192893442, 21894426987819404424310, 4616079845508388554313022889, 82759461944940747300611642693066719359651817521, 446*(2^445-7)/1061319625781480182060453906975 (107 digits). - Max Alekseyev, Oct 03 2016

LINKS

Table of n, a(n) for n=1..18.

Joe K. Crump, 2^n mod n

MATHEMATICA

For[n=1, n<= 10^6, n++, If[PowerMod[2, n, n] == Mod[14, n], Print[n]]] (* Stefan Steinerberger, May 05 2007 *)

m = 14; Join[Select[Range[m], Divisible[2^# - m, #] &],

Select[Range[m + 1, 10^6], PowerMod[2, #, #] == m &]] (* Robert Price, Oct 08 2018 *)

CROSSREFS

Cf. A015910, A036236, A050259 = numbers n such that 2^n == 3 (mod n), A033981, A051447, A033982, A051446, A033983, A128121, A128122, A128123, A128124, A128126.

Sequence in context: A270442 A184163 A218271 * A070239 A002443 A111788

Adjacent sequences:  A128122 A128123 A128124 * A128126 A128127 A128128

KEYWORD

hard,more,nonn

AUTHOR

Alexander Adamchuk, Feb 15 2007

EXTENSIONS

1, 2, 3 and 10 added by N. J. A. Sloane, Apr 23 2007

More terms from Stefan Steinerberger, May 05 2007

a(13) from Max Alekseyev, May 15 2011

a(14),a(16),a(17) from Max Alekseyev, Dec 16 2013

a(15),a(18) from Max Alekseyev, Oct 03 2016

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 20 22:51 EST 2019. Contains 320362 sequences. (Running on oeis4.)