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 A318879 #10 Sep 05 2018 17:18:24
%S A318879 0,0,0,0,0,2,0,0,0,2,0,6,0,2,0,0,0,8,0,6,0,2,0,14,0,2,0,6,0,18,0,0,0,
%T A318879 2,0,24,0,2,0,14,0,22,0,6,0,2,0,30,0,12,0,6,0,26,0,14,0,2,0,54,0,2,0,
%U A318879 0,0,30,0,6,0,26,0,56,0,2,0,6,0,34,0,30,0,2,0,66,0,2,0,14,0,66,0,6,0,2,0,62,0,16,0,36,0,42,0,14,9
%N A318879 a(n) = Sum_{d|n} [d-(2*phi(d)) > 0]*(d-(2*phi(d))).
%H A318879 Antti Karttunen, <a href="/A318879/b318879.txt">Table of n, a(n) for n = 1..65537</a>
%F A318879 a(n) = -Sum_{d|n} [A083254(d) < 0]*A083254(d), where A083254(n) = 2*phi(n) - n, and [ ] are the Iverson brackets.
%F A318879 a(n) = A318878(n) - A033879(n).
%e A318879 n = 105 has divisors [1, 3, 5, 7, 15, 21, 35, 105]. When A083254 is applied to them, we obtain [1, 1, 3, 5, 1, 3, 13, -9]. Summing the negative numbers present, and negating, we get a(105) = -(-9) = 9.
%o A318879 (PARI) A318879(n) = sumdiv(n,d,d=d-(2*eulerphi(d)); (d>0)*d);
%Y A318879 Cf. A000010, A033879, A083254, A318878.
%Y A318879 Cf. also A318679.
%K A318879 nonn
%O A318879 1,6
%A A318879 _Antti Karttunen_, Sep 05 2018