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 A062963 #28 Apr 21 2024 11:39:31
%S A062963 -1,-1,0,-2,1,-3,0,0,2,-5,0,-6,3,4,0,-8,0,-9,0,6,5,-11,0,0,6,0,0,-14,
%T A062963 -4,-15,0,10,8,12,0,-18,9,12,0,-20,-6,-21,0,0,11,-23,0,0,0,16,0,-26,0,
%U A062963 20,0,18,14,-29,0,-30,15,0,0,24,-10,-33,0,22,-12,-35,0,-36,18,0,0,30,-12,-39,0,0,20,-41,0,32,21,28,0,-44,0,36,0,30,23,36
%N A062963 a(n) = mu(n) * H(n) where H(n) is A023022.
%H A062963 Paolo Xausa, <a href="/A062963/b062963.txt">Table of n, a(n) for n = 2..10000</a>
%F A062963 a(n) = A008683(n) * A023022(n).
%t A062963 Join[{-1}, Array[MoebiusMu[#] * EulerPhi[#]/2 &, 100, 3]] (* _Paolo Xausa_, Apr 17 2024 *)
%o A062963 (PARI) a(n) = if(n<=2, -1, eulerphi(n)/2*moebius(n)); \\ _Michel Marcus_, Apr 14 2024
%Y A062963 Cf. A008683, A023022.
%K A062963 easy,sign
%O A062963 2,4
%A A062963 _Jason Earls_, Jul 22 2001