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!)
A116622 Positive integers n such that 13^n == 2 (mod n). 13
1, 11, 140711, 863101, 1856455, 115602923, 566411084209, 706836043419179 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

No other terms below 10^16. - Max Alekseyev, Nov 02 2018

LINKS

Table of n, a(n) for n=1..8.

MATHEMATICA

Select[Range[1, 500000], Mod[13^#, #] == 2 &] (* G. C. Greubel, Nov 19 2017 *)

PROG

(PARI) isok(n) = Mod(13, n)^n == 2; \\ Michel Marcus, Nov 19 2017

CROSSREFS

Cf. A116609.

Solutions to b^n == 2 (mod n): A015919 (b=2), A276671 (b=3), A130421 (b=4), A124246 (b=5), A277401 (b=7).

Solutions to 13^n == k (mod n): A001022 (k=0), A015963 (k=-1), A116621 (k=1), this sequence (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), A295532 (k=8), A116636 (k=9), A116620 (k=10), A116638 (k=11), A116639  (k=15)

Sequence in context: A111478 A300196 A055311 * A013794 A022009 A201249

Adjacent sequences:  A116619 A116620 A116621 * A116623 A116624 A116625

KEYWORD

more,nonn

AUTHOR

Zak Seidov, Feb 19 2006

EXTENSIONS

One more term from Ryan Propper, Jun 11 2006

Term a(1)=1 is prepended and a(7)-a(8) are added by Max Alekseyev, Jun 29 2011

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 07:28 EST 2020. Contains 332067 sequences. (Running on oeis4.)