A057231 - OEIS

%I #19 Apr 15 2020 09:51:26

%S 1,2,3,9,27,33,81,194,243,729,1647,2187,2673,6561,15957,19683,59049,

%T 133407,177147,216513,314523,531441,699597,1306833,1594323,4782969,

%U 5622777,5640273,6762933,10805967,11708163,14348907,17537553,20069451,32537457,43046721,66075831

%N Numbers k such that k divides 9^k + 8^k + 7^k.

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

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

%Y Supersequence of A000244.

%Y Cf. A074580.

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Sep 20 2000

%E a(24)-a(29) from _Robert Israel_, Jan 29 2020

%E More terms from _Jinyuan Wang_, Apr 15 2020