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 A074943 #15 Apr 16 2024 02:40:02
%S A074943 1,2,2,0,2,1,2,1,0,1,2,0,2,1,1,2,2,0,2,0,1,1,2,2,0,1,1,0,2,2,2,0,1,1,
%T A074943 1,0,2,1,1,2,2,2,2,0,0,1,2,1,0,0,1,0,2,2,1,2,1,1,2,0,2,1,0,1,1,2,2,0,
%U A074943 1,2,2,0,2,1,0,0,1,2,2,1,2,1,2,0,1,1,1,2,2,0,1,0,1,1,1,0,2,0,0,0,2,2,2,2,2
%N A074943 a(n) = tau(n) mod 3.
%H A074943 Antti Karttunen, <a href="/A074943/b074943.txt">Table of n, a(n) for n = 1..10000</a>
%H A074943 <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a>.
%F A074943 From _Amiram Eldar_, Apr 16 2024: (Start)
%F A074943 a(n) = A010872(A000005(n)).
%F A074943 a(A059269(n)) = 0; a(A211337(n)) = 1; a(A211338(n)) = 2.
%F A074943 Conjecture: Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 9*zeta(3)/Pi^2 = 1.0961... . The conjecture is true if A211337 and A211338 have the same asymptotic density (see also A059269). (End)
%t A074943 Mod[DivisorSigma[0,Range[110]],3] (* _Harvey P. Dale_, Dec 22 2013 *)
%o A074943 (PARI) a(n)=numdiv(n)%3
%o A074943 (Scheme) (define (A074943 n) (modulo (A000005 n) 3)) ;; _Antti Karttunen_, Jul 26 2017
%Y A074943 Cf. A000005 (tau), A002117, A010872, A059269, A211337, A211338.
%K A074943 easy,nonn
%O A074943 1,2
%A A074943 _Benoit Cloitre_, Oct 04 2002