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 A199443 #8 Feb 08 2025 09:19:13
%S A199443 4,3,0,3,0,7,4,4,1,9,2,1,5,3,5,2,9,7,9,2,1,6,4,5,9,0,1,9,0,4,2,7,5,9,
%T A199443 0,4,5,0,1,3,7,8,7,7,7,3,6,0,7,0,8,5,0,2,8,9,8,9,6,3,5,9,6,2,9,6,3,7,
%U A199443 0,1,6,3,0,0,9,0,4,2,3,8,5,7,6,1,4,2,2,2,2,4,1,0,0,1,5,5,6,4,4
%N A199443 Decimal expansion of x>0 satisfying 2*x^2+3*x*sin(x)=cos(x).
%C A199443 See A199370 for a guide to related sequences. The Mathematica program includes a graph.
%H A199443 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199443 0.430307441921535297921645901904275904501378777...
%t A199443 a = 2; b = 3; c = 1;
%t A199443 f[x_] := a*x^2 + b*x*Sin[x]; g[x_] := c*Cos[x]
%t A199443 Plot[{f[x], g[x]}, {x, -Pi, Pi}, {AxesOrigin -> {0, 0}}]
%t A199443 r = x /. FindRoot[f[x] == g[x], {x, .43, .44}, WorkingPrecision -> 110]
%t A199443 RealDigits[r] (* A199443 *)
%Y A199443 Cf. A199429.
%K A199443 nonn,cons
%O A199443 0,1
%A A199443 _Clark Kimberling_, Nov 06 2011