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 A339701 #5 Dec 14 2020 10:28:26
%S A339701 1,-2,-2,-1,-2,2,-2,2,-1,2,-2,4,-2,2,2,1,-2,4,-2,4,2,2,-2,0,-1,2,2,4,
%T A339701 -2,2,-2,2,2,2,2,0,-2,2,2,0,-2,2,-2,4,4,2,-2,-2,-1,4,2,4,-2,0,2,0,2,2,
%U A339701 -2,-4,-2,2,4,-2,2,2,-2,4,2,2,-2,-4,-2,2,4,4,2,2,-2,-2
%N A339701 Dirichlet g.f.: Product_{k>=2} (1 - k^(-s))^2.
%F A339701 a(1) = 1; a(n) = -Sum_{d|n, d < n} A301830(n/d) * a(d).
%F A339701 a(n) = Sum_{d|n} A114592(n/d) * A114592(d).
%F A339701 a(p^k) = A002107(k) for prime p.
%Y A339701 Cf. A002107, A114592, A301830, A339702, A339703, A339704, A339705, A339706, A339707.
%K A339701 sign
%O A339701 1,2
%A A339701 _Ilya Gutkovskiy_, Dec 13 2020