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 A229121 #29 Sep 16 2023 05:27:08
%S A229121 0,0,0,3,0,0,0,8,3,0,0,5,0,0,0,15,0,5,0,5,0,0,0,12,3,0,8,5,0,0,0,24,0,
%T A229121 0,0,12,0,0,0,12,0,0,0,5,5,0,0,21,3,5,0,5,0,12,0,12,0,0,0,7,0,0,5,35,
%U A229121 0,0,0,5,0,0,0,21,0,0,5,5,0,0,0,21,15,0,0
%N A229121 a(n) = Omega(n)^2 - omega(n)^2.
%C A229121 If n is squarefree, a(n) = 0. If n is a semiprime, then a(n) = 3 - 3 * mu(n).
%H A229121 T. D. Noe, <a href="/A229121/b229121.txt">Table of n, a(n) for n = 1..10000</a>
%F A229121 a(n) = A001222(n)^2 - A001221(n)^2.
%F A229121 a(n) = A046660(n) * A080256(n). - _Amiram Eldar_, Sep 16 2023
%p A229121 with(numtheory); A001221 := proc(n) nops(numtheory[factorset](n)) end: seq(bigomega(k)^2 - A001221(k)^2, k=1..100);
%t A229121 Table[PrimeOmega[n]^2 - PrimeNu[n]^2, {n, 100}] (* _T. D. Noe_, Sep 17 2013 *)
%Y A229121 Cf. A001221 (omega), A001222 (Omega), A046660 (difference), A080256 (sum).
%K A229121 nonn,easy
%O A229121 1,4
%A A229121 _Wesley Ivan Hurt_, Sep 17 2013