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!)
A057231 Numbers k such that k divides 9^k + 8^k + 7^k. 0
1, 2, 3, 9, 27, 33, 81, 194, 243, 729, 1647, 2187, 2673, 6561, 15957, 19683, 59049, 133407, 177147, 216513, 314523, 531441, 699597, 1306833, 1594323, 4782969, 5622777, 5640273, 6762933, 10805967, 11708163, 14348907, 17537553, 20069451, 32537457, 43046721, 66075831 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..37.

MAPLE

select(t -> (9 &^ t + 8 &^ t + 7 &^ t) mod t = 0, [$1..10^7]); # Robert Israel, Jan 29 2020

MATHEMATICA

Select[ Range[ 10^6 ], Mod[ PowerMod[ 9, #, # ] + PowerMod[ 8, #, # ] + PowerMod[ 7, #, # ], # ] == 0 & ]

CROSSREFS

Supersequence of A000244.

Cf. A074580.

Sequence in context: A096237 A309814 A177928 * A178028 A045596 A057299

Adjacent sequences:  A057228 A057229 A057230 * A057232 A057233 A057234

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 20 2000

EXTENSIONS

a(24)-a(29) from Robert Israel, Jan 29 2020

More terms from Jinyuan Wang, Apr 15 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 August 14 04:03 EDT 2020. Contains 336477 sequences. (Running on oeis4.)