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 A062984 #21 May 03 2024 04:19:41
%S A062984 0,0,0,0,0,-2,0,-1,-1,-2,0,-1,0,-2,-2,-2,0,-3,0,-2,-1,-3,0,-1,-2,-1,
%T A062984 -2,-1,0,-1,0,-3,-2,-3,-2,-3,0,-2,-1,-3,0,-3,0,0,-4,-2,0,-3,-2,-2,-3,
%U A062984 -3,0,0,-1,-1,-1,-4,0,-3,0,-3,0,-1,-2,-2,0,-1,-1,-4,0,-2,0,0,-3,-1,-2,-2,0,-3,0,-3,0,-4,-1,-3,-4,-1,0,-1,-3,-3,-2,-3
%N A062984 a(n) = M(C(n)), where M(n) is Mertens's function (A002321) and C(n) is Chowla's function (A048050).
%H A062984 Harry J. Smith, <a href="/A062984/b062984.txt">Table of n, a(n) for n = 1..2000</a>
%t A062984 A062984[n_] := Sum[MoebiusMu[k], {k, DivisorSigma[1, n] - n - 1}];
%t A062984 Array[A062984, 100] (* _Paolo Xausa_, May 03 2024 *)
%o A062984 (PARI) M(n)=sum(k=1,n,moebius(k));
%o A062984 C(n)=sigma(n)-n-1;
%o A062984 j=[]; for(n=1,350,j=concat(j,M(C(n)))); j
%o A062984 (PARI) { for (n=1, 2000, a=sum(k=1, sigma(n) - n - 1, moebius(k)); write("b062984.txt", n, " ", a) ) } \\ _Harry J. Smith_, Aug 15 2009
%Y A062984 Cf. A002321, A048050.
%K A062984 easy,sign
%O A062984 1,6
%A A062984 _Jason Earls_, Jul 25 2001