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 A197850 #6 Feb 07 2025 16:44:04
%S A197850 2,6,6,7,0,2,8,4,6,4,1,0,5,8,0,1,7,9,2,6,3,5,5,4,2,1,2,9,4,9,8,3,9,9,
%T A197850 7,4,5,8,1,5,6,8,7,8,0,8,6,3,0,3,0,2,9,7,8,5,5,1,5,5,7,5,5,6,9,0,1,1,
%U A197850 4,1,9,8,8,3,6,3,1,8,2,9,4,1,9,1,0,4,6,8,2,6,2,6,1,3,4,5,2,3,9
%N A197850 Decimal expansion of greatest x having x^2-2x=-2*cos(x).
%C A197850 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A197850 least x: 1.0485583594904940957585652640454931931...
%e A197850 greatest x: 2.66702846410580179263554212949839974
%t A197850 a = 1; b = -2; c = -2;
%t A197850 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A197850 Plot[{f[x], g[x]}, {x, 0, 3}]
%t A197850 r1 = x /. FindRoot[f[x] == g[x], {x, 1, 1.1}, WorkingPrecision -> 110]
%t A197850 RealDigits[r1] (* A197849 *)
%t A197850 r2 = x /. FindRoot[f[x] == g[x], {x, 2.6, 2.7}, WorkingPrecision -> 110]
%t A197850 RealDigits[r2] (* A197850 *)
%Y A197850 Cf. A197737.
%K A197850 nonn,cons
%O A197850 1,1
%A A197850 _Clark Kimberling_, Oct 21 2011