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 A353233 #38 Jun 08 2023 00:20:09
%S A353233 1,4,27,268,3125,47418,823543,16842736,387440145,10009763520,
%T A353233 285311670611,8918294495628,302875106592253,11112685047823702,
%U A353233 437893920912783255,18447025552964452096,827240261886336764177,39346558271491791438000,1978419655660313589123979
%N A353233 Möbius transform of sigma_n(n).
%H A353233 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>.
%F A353233 a(n) = Sum_{d|n} sigma_d(d) * mu(n/d).
%e A353233 a(6) = 47418; a(6) = Sum_{d|6} sigma_d(d) * mu(6/d) = sigma_1(1) * mu(6/1) + sigma_2(2) * mu(6/2) + sigma_3(3) * mu(6/3) + sigma_6(6) * mu(6/6) = 1*1 + 5*(-1) + 28*(-1) + 47450*1 = 47418.
%t A353233 a[n_] := DivisorSum[n, DivisorSigma[#, #]*MoebiusMu[n/#] &]; Array[a, 20] (* _Wesley Ivan Hurt_, Nov 12 2022 *)
%o A353233 (PARI) a(n) = sumdiv(n, d, sigma(d,d)*moebius(n/d)); \\ _Michel Marcus_, Jun 24 2022
%Y A353233 Cf. A008683 (mu), A023887.
%K A353233 nonn
%O A353233 1,2
%A A353233 _Wesley Ivan Hurt_, Jun 24 2022