This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A057286 #10 Jul 31 2025 14:31:09
%S A057286 1,3,7,9,21,27,49,63,69,81,119,147,189,243,343,441,567,729,1029,1269,
%T A057286 1323,1701,2187,2401,3087,3357,3969,5103,5271,5831,6561,7203,9261,
%U A057286 9639,11907,15309,16767,16807,19683,20727,21609,24451,27783,30429,35077
%N A057286 Numbers k such that k | 11^k + 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k.
%t A057286 Select[ Range[ 10^5 ], Mod[ PowerMod[ 11, #, # ] + PowerMod[ 10, #, # ] + PowerMod[ 9, #, # ] + PowerMod[ 8, #, # ] + PowerMod[ 7, #, # ] + PowerMod[ 6, #, # ] + PowerMod[ 5, #, # ] + PowerMod[ 4, #, # ] + PowerMod[ 3, #, # ], # ] == 0 & ]
%t A057286 Select[Range[36000],Mod[Total[Table[PowerMod[n,#,#],{n,3,11}]],#] == 0&] (* This program is essentially equivalent to the above program. *) (* _Harvey P. Dale_, Jun 09 2021 *)
%K A057286 nonn
%O A057286 1,2
%A A057286 _Robert G. Wilson v_, Sep 22 2000