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 A319684 #9 May 24 2021 18:17:21
%S A319684 0,1,1,5,1,7,1,17,7,9,1,27,1,11,10,49,1,34,1,37,12,15,1,83,11,17,34,
%T A319684 47,1,54,1,129,16,21,14,114,1,23,18,117,1,68,1,67,55,27,1,227,15,64,
%U A319684 22,77,1,142,18,151,24,33,1,190,1,35,69,321,20,96,1,97,28,90,1,326,1,41,75,107,20,110,1,325,142,45,1,244,24,47,34,219,1,243,22
%N A319684 Sum of A003415(d) over the divisors d of n, where A003415 is arithmetic derivative.
%C A319684 Inverse Möbius transform of A003415.
%H A319684 Antti Karttunen, <a href="/A319684/b319684.txt">Table of n, a(n) for n = 1..65537</a>
%F A319684 a(n) = Sum_{d|n} A003415(d).
%F A319684 a(n) = A319683(n) + A003415(n).
%t A319684 Block[{a}, a[1] = 0; a[n_] := a[n] = If[n < 2, 0, n Total[#2/#1 & @@@ FactorInteger[n]]]; Array[DivisorSum[#, a[#] &] &, 91]] (* _Michael De Vlieger_, May 24 2021 *)
%o A319684 (PARI)
%o A319684 A003415(n) = {my(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]))}; \\ From A003415
%o A319684 A319684(n) = sumdiv(n,d,A003415(d));
%Y A319684 Cf. A003415, A319683.
%Y A319684 Cf. also A300251, A300252, A305809, A317835.
%K A319684 nonn
%O A319684 1,4
%A A319684 _Antti Karttunen_, Oct 02 2018