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 A322513 #33 Oct 08 2019 17:08:46
%S A322513 0,1,1,-2,1,11,-48,-6,1241,-6431,-15320,452970,-2317212,-17584137,
%T A322513 372119776,-1552313624,-31732274313,565880016193,-1217992446564,
%U A322513 -90197542736656,1400682677566587,1990004001731140,-384348195167184028,5109122826021406702
%N A322513 Expansion of e.g.f. log(1 + Sum_{k>=1} d(k) * x^k / k!), where d(k) = number of divisors of k (A000005).
%C A322513 Logarithmic transform of A000005.
%H A322513 Alois P. Heinz, <a href="/A322513/b322513.txt">Table of n, a(n) for n = 0..470</a>
%p A322513 a:= proc(n) option remember; `if`(n=0, 0, (b-> b(n)-add(a(j)
%p A322513 *binomial(n, j)*j*b(n-j), j=1..n-1)/n)(numtheory[tau]))
%p A322513 end:
%p A322513 seq(a(n), n=0..25); # _Alois P. Heinz_, Oct 06 2019
%t A322513 nmax = 23; CoefficientList[Series[Log[1 + Sum[DivisorSigma[0, k] x^k/k!, {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
%t A322513 a[n_] := a[n] = DivisorSigma[0, n] - Sum[Binomial[n, k] DivisorSigma[0, n - k] k a[k], {k, 1, n - 1}]/n; a[0] = 0; Table[a[n], {n, 0, 23}]
%Y A322513 Cf. A000005, A028342, A274805, A294363, A295739.
%K A322513 sign
%O A322513 0,4
%A A322513 _Ilya Gutkovskiy_, Oct 03 2019