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 A333121 #8 Mar 08 2020 08:39:13
%S A333121 1,2,6,14,90,182,7686,15374,1383750,19372514,10577393190,21154786382,
%T A333121 2438935322096070,4877870644192142,224977149851430019446,
%U A333121 286620888910721844775478,396611655030211352708069066250,793223310060422705416138132502,8436334593920261958919014477018674175558
%N A333121 a(1) = 1; a(n+1) = Product_{d|n} (1 + a(d)).
%t A333121 a[1] = 1; a[n_] := a[n] = Product[1 + a[d], {d, Divisors[n - 1]}]; Table[a[n], {n, 1, 19}]
%Y A333121 Cf. A007018, A020696, A066843, A068334.
%K A333121 nonn
%O A333121 1,2
%A A333121 _Ilya Gutkovskiy_, Mar 08 2020