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 A353818 #6 May 10 2022 14:26:28
%S A353818 1,0,1,-4,29,-174,1583,-13168,144153,-1485330,20127867,-253341144,
%T A353818 3978820221,-57986205900,1057400360235,-18016221644544,
%U A353818 370244721585681,-6993826454599146,162968423791332339,-3490951922268853320,88052648301403014789,-2075060448716599488276
%N A353818 Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + arcsin(x).
%t A353818 nn = 22; f[x_] := Product[(1 + a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - ArcSin[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten
%Y A353818 Cf. A001818, A006973, A137852, A353607, A353819, A353820, A353821.
%K A353818 sign
%O A353818 1,4
%A A353818 _Ilya Gutkovskiy_, May 08 2022