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 A344584 #15 Dec 09 2021 01:30:59 %S A344584 0,0,0,2,0,1,0,10,3,1,0,11,0,1,1,34,0,13,0,15,1,1,0,47,5,1,21,19,0,12, %T A344584 0,98,1,1,1,59,0,1,1,67,0,14,0,27,22,1,0,151,7,21,1,31,0,76,1,87,1,1, %U A344584 0,82,0,1,28,258,1,18,0,39,1,16,0,203,0,1,26,43,1,20,0,219,102,1,0,104,1,1,1,127,0,99,1,51,1,1,1,423 %N A344584 Difference between the inverse Möbius transform of the arithmetic derivative of n and the sum of the proper divisors of n: a(n) = A319684(n) - A001065(n). %H A344584 Antti Karttunen, <a href="/A344584/b344584.txt">Table of n, a(n) for n = 1..20000</a> %F A344584 a(n) = A319684(n) - A001065(n) = A211991(n) + A319683(n). %F A344584 a(n) = Sum_{d|n} A344178(d). %F A344584 a(n) = n + Sum_{d|n} A168036(d). %t A344584 Block[{a}, a[1] = 0; a[n_] := a[n] = If[n < 2, 0, n Total[#2/#1 & @@@ FactorInteger[n]]]; Array[DivisorSum[#, a[#] &] - DivisorSigma[1, #] + # &, 96]] (* _Michael De Vlieger_, May 24 2021 *) %o A344584 (PARI) %o A344584 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A344584 A319684(n) = sumdiv(n, d, A003415(d)); %o A344584 A344584(n) = (A319684(n) - (sigma(n)-n)); %Y A344584 Cf. A000203, A001065, A003415, A168036, A211991, A319683, A319684. %Y A344584 Inverse Möbius transform of A344178. %K A344584 nonn %O A344584 1,4 %A A344584 _Antti Karttunen_, May 24 2021