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 A239641 #13 Aug 05 2018 13:39:54
%S A239641 1,-1,-2,-1,-4,2,-6,1,-2,4,-10,4,-12,6,12,-1,-16,2,-18,8,18,10,-22,-4,
%T A239641 -4,12,-2,12,-28,-12,-30,-3,30,16,36,0,-36,18,36,-8,-40,-18,-42,20,4,
%U A239641 22,-46,0,-6,4,48,24,-52,2,60,-12,54,28,-58,-40,-60,30,18,-1,84,-30,-66,32,66,-36,-70,0
%N A239641 Dirichlet inverse of Carmichael lambda function (A002322).
%H A239641 Andrew Howroyd, <a href="/A239641/b239641.txt">Table of n, a(n) for n = 1..1000</a>
%t A239641 inverse[F_][1] := 1/F[1]; inverse[F_][n_] := -1/F[1] Sum[F[n/Divisors[n][[i]]]*inverse[F][Divisors[n][[i]]], {i, Length[Divisors[n]] - 1}];Table[inverse[CarmichaelLambda][n], {n, 1, 331}];
%o A239641 (PARI) seq(n)={dirdiv(vector(n, n, n==1), vector(n, n, lcm(znstar(n).cyc)))} \\ _Andrew Howroyd_, Aug 05 2018
%Y A239641 Cf. A002322, A141258.
%K A239641 sign
%O A239641 1,3
%A A239641 _José María Grau Ribas_, Mar 23 2014