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 A300252 #13 Mar 14 2018 03:48:58
%S A300252 0,0,0,1,0,2,0,4,1,2,0,8,0,2,2,12,0,10,0,10,2,2,0,24,1,2,6,12,0,17,0,
%T A300252 32,2,2,2,32,0,2,2,32,0,21,0,16,13,2,0,64,1,16,2,18,0,42,2,40,2,2,0,
%U A300252 56,0,2,15,80,2,29,0,22,2,25,0,88,0,2,17,24,2,33,0,88,27,2,0,72,2,2,2,56,0,73,2,28,2,2,2,160,0,22,19,62,0,41,0,64,27
%N A300252 Difference between arithmetic derivative (A003415) and its Möbius transform (A300251).
%H A300252 Antti Karttunen, <a href="/A300252/b300252.txt">Table of n, a(n) for n = 1..65537</a>
%F A300252 a(n) = A003415(n) - A300251(n).
%F A300252 a(n) = -Sum_{d|n, d<n} A008683(n/d)*A003415(d).
%o A300252 (PARI)
%o A300252 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 A300252 A300252(n) = -sumdiv(n,d,(d<n)*moebius(n/d)*A003415(d));
%Y A300252 Cf. A003415, A300245, A300251, A300253.
%Y A300252 Cf. A001248 (seems to give the positions of 1's), A006881 (seems to give the positions of 2's).
%K A300252 nonn
%O A300252 1,6
%A A300252 _Antti Karttunen_, Mar 08 2018