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 A324045 #6 Feb 14 2019 07:46:56 %S A324045 1,0,0,1,0,2,0,2,5,0,0,0,0,-2,-4,6,0,-6,0,-8,-8,-6,0,-4,7,-8,17,12,0, %T A324045 -16,0,13,17,-12,15,-3,0,-14,19,6,0,6,0,8,-12,-18,0,4,9,-1,23,6,0,0, %U A324045 36,-8,25,-24,0,-32,0,-26,33,29,40,-10,0,2,29,-34,0,12,0,-32,37,0,40,-18,0,-24,12,-36,0,-4,48,-38,35,-36,0,-30,44,-4,37,-42,52,-16,0 %N A324045 a(n) = A000010(n) - A106316(n). %H A324045 Antti Karttunen, <a href="/A324045/b324045.txt">Table of n, a(n) for n = 1..20000</a> %F A324045 a(n) = A000010(n) - A106316(n). %o A324045 (PARI) %o A324045 A106315(n) = (n*numdiv(n) % sigma(n)); %o A324045 A106316(n) = (A106315(n) % n); %o A324045 A324045(n) = (eulerphi(n) - A106316(n)); %Y A324045 Cf. A000005, A000010, A000203, A106316, A324046, A324047. %K A324045 sign %O A324045 1,6 %A A324045 _Antti Karttunen_, Feb 13 2019