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 A318441 #7 Aug 27 2018 22:30:01
%S A318441 1,1,2,1,4,1,6,1,5,3,10,-3,12,5,7,1,16,-1,18,-1,11,9,22,-11,19,11,14,
%T A318441 1,28,-5,30,1,19,15,23,-19,36,17,23,-9,40,-3,42,5,14,21,46,-27,41,11,
%U A318441 31,7,52,-7,39,-7,35,27,58,-45,60,29,24,1,47,1,66,11,43,7,70,-55,72,35,30,13,59,3,78,-25,41,39,82,-51,63,41,55,-3,88
%N A318441 a(n) = Sum_{d|n} [moebius(n/d) > 0]*A033879(d).
%H A318441 Antti Karttunen, <a href="/A318441/b318441.txt">Table of n, a(n) for n = 1..65537</a>
%F A318441 a(n) = Sum_{d|n} [A008683(n/d) == 1]*A033879(d).
%F A318441 a(n) = A291784(n) - A318325(n).
%F A318441 A083254(n) = a(n) - A318442(n).
%o A318441 (PARI) A318441(n) = sumdiv(n,d,(1==moebius(n/d))*(d+d-sigma(d)));
%Y A318441 Cf. A033879, A083254, A291784, A318325, A318442.
%K A318441 sign
%O A318441 1,3
%A A318441 _Antti Karttunen_, Aug 26 2018