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!)
A337830 Odd integers k such that 6^((k-1)/2) + 1 == 0 (mod k*(k-1)/2). 0
2843, 2390123, 9893003, 16236347, 46353707, 334358459, 564092747, 584214107, 1640200619, 2010092603, 14044030043, 22315857803, 23753097803 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Computed terms are prime.

Conjecture: a(n) == 1 mod 406 for n > 5. - Chai Wah Wu, Oct 07 2020

LINKS

Table of n, a(n) for n=1..13.

MATHEMATICA

Select[Range[3, 10^7, 2], PowerMod[6, (# - 1)/2, (t = #*(# - 1)/2)] == t - 1 &] (* Amiram Eldar, Sep 24 2020 *)

CROSSREFS

Cf. A337818.

Sequence in context: A205059 A232762 A284888 * A317472 A317473 A257155

Adjacent sequences:  A337827 A337828 A337829 * A337831 A337832 A337833

KEYWORD

nonn,more

AUTHOR

Benoit Cloitre, Sep 24 2020

EXTENSIONS

a(6)-a(13) from Amiram Eldar, Sep 24 2020

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 November 29 14:07 EST 2021. Contains 349416 sequences. (Running on oeis4.)