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 A074942 #18 Sep 08 2022 08:45:07
%S A074942 1,1,2,2,1,2,0,1,0,1,1,1,0,0,2,2,1,0,0,2,0,1,1,2,2,0,0,0,1,2,0,1,2,1,
%T A074942 0,0,0,0,0,1,1,0,0,2,0,1,1,1,0,2,2,0,1,0,1,0,0,1,1,1,0,0,0,2,0,2,0,2,
%U A074942 2,0,1,0,0,0,1,0,0,0,0,2,0,1,1,0,1,0,2,1,1,0,0,2,0,1,0,2,0,0,0,1,1,2,0,0,0
%N A074942 a(n) = phi(n) mod 3.
%H A074942 Antti Karttunen, <a href="/A074942/b074942.txt">Table of n, a(n) for n = 1..10000</a>
%F A074942 a(n) = A000010(n) mod 3.
%F A074942 a(n) = A010872(A000010(n)). - _Michel Marcus_, Sep 05 2015
%t A074942 Table[Mod[EulerPhi[n], 3], {n, 100}] (* _Vincenzo Librandi_, Sep 04 2015 *)
%o A074942 (PARI) a(n)=eulerphi(n)%3
%o A074942 (Magma) [EulerPhi(n) mod 3: n in [1..110]]; // _Vincenzo Librandi_, Sep 04 2015
%Y A074942 Cf. A000010, A010872, A074943, A084300.
%K A074942 easy,nonn
%O A074942 1,3
%A A074942 _Benoit Cloitre_, Oct 04 2002