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 A334313 #26 May 06 2020 02:45:30
%S A334313 1,2,3,12,5,60,210,840,63,2520,770,5544,25740,40040,90090,720720,
%T A334313 510510,12252240,58198140,232792560,5290740,3695120,148728580,
%U A334313 5354228880,147094200,26771144400,5019589575,80313433200,2587877292,2329089562800,36100888223400,3702655202400
%N A334313 Denominators of the partial sums of the Möbius transform of the harmonic numbers.
%F A334313 a(n) = denominator of Sum_{m=1..n} Sum_{d|m} H(d)*mu(m/d).
%F A334313 A334314(n)/a(n) = Sum_{k=1..n} A334312(n,k)/k.
%t A334313 nn = 32; Denominator[Table[Sum[Sum[If[Mod[n, k] == 0, MoebiusMu[n/k]*HarmonicNumber[k], 0], {k, 1, n}], {n, 1, m}], {m, 1, nn}]]
%o A334313 (PARI) a(n) = denominator(sum(m=1, n, sumdiv(m, d, moebius(m/d)*sum(i=1, d, 1/i)))); \\ _Michel Marcus_, Apr 23 2020
%Y A334313 Numerators are in A334314.
%Y A334313 Cf. A334312.
%K A334313 nonn,frac
%O A334313 1,2
%A A334313 _Mats Granvik_, Apr 23 2020