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 A349436 #10 Nov 21 2021 01:19:08
%S A349436 2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,0,0,
%T A349436 0,12,0,0,0,0,0,0,0,0,0,0,0,-8,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,20,0,0,0,
%U A349436 0,0,0,0,0,0,0,0,0,0,0,0,-8,9,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-8,0,0,0,20,0,0,0,0,0,0,0,12
%N A349436 a(n) = A349434(n) + A349435(n).
%H A349436 Antti Karttunen, <a href="/A349436/b349436.txt">Table of n, a(n) for n = 1..20000</a>
%F A349436 a(1) = 2, and for n >1, a(n) = -Sum_{d|n, 1<d<n} A349434(d) * A349435(n/d). [As the sequences are Dirichlet inverses of each other]
%t A349436 s[n_] := n * DivisorSum[n, 1/# &, !CompositeQ[#] &]; sinv[1] = 1; sinv[n_] := sinv[n] = -DivisorSum[n, sinv[#] * s[n/#] &, # < n &]; f[p_, e_] := e/p; d[1] = 1; d[n_] := n*(1 + Plus @@ f @@@ FactorInteger[n]); dinv[1] = 1; dinv[n_] := dinv[n] = -DivisorSum[n, dinv[#] * d[n/#] &, # < n &]; a[n_] := DivisorSum[n, dinv[#] * s[n/#] + sinv[#] * d[n/#] &]; Array[a, 100] (* _Amiram Eldar_, Nov 18 2021 *)
%o A349436 (PARI) A349436(n) = (A349434(n) + A349435(n)); \\ Needs also code from A349434 and A349435.
%Y A349436 Cf. A349434, A349435.
%K A349436 sign
%O A349436 1,1
%A A349436 _Antti Karttunen_, Nov 17 2021