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 A341698 #6 Feb 17 2021 20:29:43
%S A341698 1,1,-1,1,-2,2,0,0,-2,1,3,-3,1,-1,1,-5,4,-4,12,-12,14,-14,8,-8,10,-14,
%T A341698 12,-16,18,-18,26,-26,36,-30,22,-22,24,-24,0,2,20,-20,-10,10,12,-18,2,
%U A341698 -2,14,-14,-2,10,16,-16,-8,20,14,10,-46,46,-52,52,-104,132,-70,74,-186,186,-134,150
%N A341698 a(1) = a(2) = 1; a(n+1) = -Sum_{d|n, d < n} a(n/d) * a(d).
%t A341698 a[1] = a[2] = 1; a[n_] := a[n] = -Sum[If[d < (n - 1), a[(n - 1)/d] a[d], 0], {d, Divisors[n - 1]}]; Table[a[n], {n, 70}]
%o A341698 (PARI) A341698(n) = if(n<3, 1, sumdiv(n-1,d,if(d<(n-1), -A341698((n-1)/d)*A341698(d), 0))); \\ _Antti Karttunen_, Feb 17 2021
%Y A341698 Cf. A038044, A325303, A341697.
%K A341698 sign
%O A341698 1,5
%A A341698 _Ilya Gutkovskiy_, Feb 17 2021