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 A062563 #18 Jun 25 2022 00:50:11
%S A062563 1,-1,-3,-3,-5,-1,-3,-3,-3,1,-1,-1,-3,1,5,5,3,3,1,1,5,9,7,7,7,11,11,
%T A062563 11,9,1,-1,-1,3,7,11,11,9,13,17,17,15,7,5,5,5,9,7,7,7,7,11,11,9,9,13,
%U A062563 13,17,21,19,19,17,21,21,21,25,17,15,15,19,11,9,9,7,11,11,11,15,7,5,5,5,9,7,7,11,15,19,19,17,17,21,21,25,29,33,33,31
%N A062563 a(n) = Sum_{k=1..n} d(k)* mu(k), where d(k) is the number of divisors function.
%F A062563 Also a(n) = Sum_{k=1..n} 2^omega(k)*mu(k). - _Benoit Cloitre_, Jun 13 2007
%t A062563 Accumulate[Table[DivisorSigma[0,n]MoebiusMu[n],{n,100}]] (* _Harvey P. Dale_, Aug 15 2016 *)
%o A062563 (PARI) v=[]; for(n=1,250,v=concat(v,sum(k=1,n,numdiv(k)*moebius(k)))); v
%Y A062563 Partial sums of A226177.
%K A062563 sign
%O A062563 1,3
%A A062563 _Jason Earls_, Jul 03 2001