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 A323911 #7 Feb 12 2019 22:37:20
%S A323911 2,0,0,1,0,4,0,1,4,8,0,-2,0,12,16,1,0,-2,0,0,24,20,0,-8,16,24,12,2,0,
%T A323911 -28,0,1,40,32,48,-15,0,36,48,-6,0,-36,0,6,16,44,0,-20,36,6,64,8,0,
%U A323911 -12,80,-4,72,56,0,-46,0,60,28,1,96,-52,0,12,88,-44,0,-39,0,72,28,14,120,-60,0,-18,37,80,0,-58,128,84,112,0,0,-52,144,18
%N A323911 Sum of deficiency of n (A033879) and its Dirichlet inverse.
%H A323911 Antti Karttunen, <a href="/A323911/b323911.txt">Table of n, a(n) for n = 1..20000</a>
%F A323911 a(n) = A033879(n) + A323910(n).
%o A323911 (PARI)
%o A323911 up_to = 16384;
%o A323911 DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(d<n, v[n/d]*u[d], 0))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v.
%o A323911 A033879(n) = (2*n-sigma(n));
%o A323911 v323910 = DirInverse(vector(up_to,n,A033879(n)));
%o A323911 A323910(n) = v323910[n];
%o A323911 A323911(n) = (A033879(n)+A323910(n));
%Y A323911 Cf. A033879, A297159, A323403, A323910, A323913.
%K A323911 sign
%O A323911 1,1
%A A323911 _Antti Karttunen_, Feb 12 2019