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 A062562 #15 Jul 18 2022 16:38:25
%S A062562 0,1,-2,-6,-6,-12,0,-8,-8,-8,10,-2,-2,-16,8,32,32,14,14,-6,-6,26,62,
%T A062562 38,38,38,80,80,80,50,-22,-54,-54,-6,48,96,96,58,118,174,174,132,36,
%U A062562 -8,-8,-8,64,16,16,16,16,88,88,34,34,106,106,186,276,216,216,154,250,250,250,334,190,122,122,218,74,2,2,-72,42,42,42
%N A062562 a(n) = Sum_{k=1..n} mu(k)*sigma(k).
%t A062562 Table[Sum[MoebiusMu[k]DivisorSigma[1,k],{k,n}],{n,0,80}] (* _Harvey P. Dale_, Nov 08 2011 *)
%o A062562 (PARI) s=[]; for(n=0,130,s=concat(s,sum(k=1,n,moebius(k)*sigma(k)))); s
%Y A062562 Partial sums of A063441.
%K A062562 sign
%O A062562 0,3
%A A062562 _Jason Earls_, Jul 03 2001
%E A062562 Corrected by _Harvey P. Dale_, Nov 08 2011