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 A369700 #14 Feb 26 2024 10:42:35
%S A369700 1,0,1,1,3,0,5,0,4,0,9,-1,11,0,-1,2,15,0,17,-1,-1,0,21,0,16,0,12,-1,
%T A369700 27,0,29,4,-1,0,3,0,35,0,-1,0,39,0,41,-1,4,0,45,0,36,0,-1,-1,51,0,7,0,
%U A369700 -1,0,57,1,59,0,-4,8,-3,0,65,-1,-1,0
%N A369700 Möbius transform of reduced totient function (A002322).
%C A369700 Since A002322(n) = A000010(n) for n = 1, 2, 4, and odd prime powers, a(n) = A007431(n) for the same values of n.
%F A369700 a(n) = Sum_{d|n} A008683(d) * A002322(n/d).
%e A369700 a(8) = mu(1)*lambda(8) + mu(2)*lambda(4) + mu(4)*lambda(2) + mu(8)*lambda(1) = 0.
%t A369700 a[n_] := DivisorSum[n, MoebiusMu[#] * CarmichaelLambda[n/#] &]; Array[a, 100] (* _Amiram Eldar_, Jan 29 2024 *)
%o A369700 (PARI) a(n) = sumdiv(n, d, moebius(d)*lcm(znstar(n/d)[2]))
%Y A369700 Cf. A008683, A002322, A000010, A007431.
%K A369700 sign
%O A369700 1,5
%A A369700 _Miles Englezou_, Jan 29 2024