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 A199504 #8 Feb 08 2025 10:00:45
%S A199504 1,2,8,6,6,8,5,6,4,4,8,1,2,6,8,3,7,2,1,5,4,6,8,2,1,3,9,6,1,2,0,2,6,7,
%T A199504 9,7,6,9,1,0,3,8,6,3,7,2,6,3,9,1,3,7,9,5,6,4,1,3,3,7,1,6,3,5,8,7,8,7,
%U A199504 3,9,4,9,5,6,3,4,5,3,7,4,1,9,7,8,0,9,8,2,9,3,0,6,0,3,8,6,2,9,6
%N A199504 Decimal expansion of x>0 satisfying 2*x^2-2*x*sin(x)=3*cos(x).
%C A199504 See A199429 for a guide to related sequences. The Mathematica program includes a graph.
%H A199504 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199504 1.286685644812683721546821396120267976910...
%t A199504 a = 2; b = -2; c = 3;
%t A199504 f[x_] := a*x^2 + b*x*Sin[x]; g[x_] := c*Cos[x]
%t A199504 Plot[{f[x], g[x]}, {x, -2 Pi, 2 Pi}, {AxesOrigin -> {0, 0}}]
%t A199504 r = x /. FindRoot[f[x] == g[x], {x, 1.28, 1.29}, WorkingPrecision -> 110]
%t A199504 RealDigits[r] (* A199504 *)
%Y A199504 Cf. A199429.
%K A199504 nonn,cons
%O A199504 1,2
%A A199504 _Clark Kimberling_, Nov 07 2011