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 A318442 #6 Aug 27 2018 22:30:08
%S A318442 0,1,1,1,1,3,1,1,2,5,1,1,1,7,6,1,1,5,1,3,8,11,1,-3,4,13,5,5,1,9,1,1,
%T A318442 12,17,10,-7,1,19,14,-1,1,15,1,9,11,23,1,-11,6,21,18,11,1,11,14,1,20,
%U A318442 29,1,-17,1,31,15,1,16,27,1,15,24,29,1,-31,1,37,25,17,16,33,1,-9,14,41,1,-15,20,43,30,5,1,-1,18,21,32,47,22,-27,1
%N A318442 a(n) = Sum_{d|n} [moebius(n/d) < 0]*A033879(d).
%H A318442 Antti Karttunen, <a href="/A318442/b318442.txt">Table of n, a(n) for n = 1..65537</a>
%F A318442 a(n) = Sum_{d|n} [A008683(n/d) == 1]*A033879(d).
%F A318442 a(n) = A318320(n) - A318326(n).
%F A318442 A083254(n) = A318441(n) - a(n).
%o A318442 (PARI) A318442(n) = sumdiv(n,d,(-1==moebius(n/d))*(d+d-sigma(d)));
%Y A318442 Cf. A033879, A083254, A318320, A318325, A318441.
%K A318442 sign
%O A318442 1,6
%A A318442 _Antti Karttunen_, Aug 26 2018