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 A116609 #18 Dec 07 2024 14:55:18
%S A116609 0,1,1,1,3,1,6,1,1,9,2,1,0,1,7,1,13,1,13,1,13,15,13,1,18,13,1,1,13,19,
%T A116609 13,1,19,33,27,1,13,17,13,1,13,1,13,5,28,31,13,1,48,49,4,13,13,1,32,1,
%U A116609 31,53,13,1,13,45,55,1,13,31,13,1,58,29,13,1,13,21,7
%N A116609 a(n) = 13^n mod n.
%H A116609 Paul Tek, <a href="/A116609/b116609.txt">Table of n, a(n) for n = 1..10000</a>
%e A116609 a(5)=3 because 13^5 = 371293 = 3 mod 5.
%t A116609 Table[PowerMod[13,k,k],{k,200}]
%o A116609 (PARI) a(n) = { lift(Mod(13, n)^n) } \\ _G. C. Greubel_, Oct 28 2017
%K A116609 nonn
%O A116609 1,5
%A A116609 _Zak Seidov_, Feb 19 2006