login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056754 Numbers n such that n | 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n + 1^n. 0

%I

%S 1,3,5,9,15,25,27,45,75,81,125,135,225,243,375,405,423,625,675,729,

%T 765,801,895,1017,1125,1175,1215,1875,2025,2125,2187,3125,3375,3645,

%U 4755,5625,6075,6561,9375,9585,10125,10935,15625,16875,17925,18225,19683

%N Numbers n such that n | 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n + 1^n.

%t Do[ If[ Mod[ PowerMod[ 9, n, n ] + PowerMod[ 8, n, n ] + PowerMod[ 7, n, n ] + PowerMod[ 6, n, n ] + PowerMod[ 5, n, n ] + PowerMod[ 4, n, n ] + PowerMod[ 3, n, n ] + PowerMod[ 2, n, n ] + 1, n ] == 0, Print[ n ] ], {n, 1, 10^6} ]

%t Select[Range[20000],Divisible[Total[Range[2,9]^# ]+1,#]&] (* _Harvey P. Dale_, Oct 09 2019 *)

%Y Cf. A001556.

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Aug 25 2000

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 January 24 19:34 EST 2022. Contains 350565 sequences. (Running on oeis4.)