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 A351787 #6 Feb 19 2022 07:22:56
%S A351787 1,2,6,18,58,174,546,1638,4986,14994,45214,135642,407838,1223514,
%T A351787 3672726,11018874,33063498,99190494,297593514,892780542,2678403690,
%U A351787 8035217622,24105833722,72317501166,216953071986,650859219322,1952579289318,5857737927786,17573218697070
%N A351787 a(1) = 1; a(n+1) = a(n) + Sum_{d|n} a(n/d) * a(d).
%F A351787 G.f.: x * ( 1 + Sum_{i>=1} Sum_{j>=1} a(i) * a(j) * x^(i*j) ) / (1 - x).
%t A351787 a[1] = 1; a[n_] := a[n] = a[n - 1] + Sum[a[(n - 1)/d] a[d], {d, Divisors[n - 1]}]; Table[a[n], {n, 1, 29}]
%Y A351787 Cf. A038044, A084978, A122698, A277120, A339755, A341697, A345139, A351788.
%K A351787 nonn
%O A351787 1,2
%A A351787 _Ilya Gutkovskiy_, Feb 19 2022