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 A197844 #6 Feb 07 2025 16:44:04
%S A197844 6,2,0,7,6,2,3,3,6,5,8,6,6,1,4,7,1,4,4,5,2,1,2,0,2,4,7,3,2,1,5,1,5,3,
%T A197844 7,1,4,4,3,4,1,1,7,7,8,5,8,7,1,4,0,9,1,6,4,2,4,8,3,0,0,9,3,7,3,1,1,0,
%U A197844 4,9,0,2,1,6,0,2,3,6,8,0,1,5,1,6,3,7,1,7,0,3,1,1,5,2,5,5,7,6,2
%N A197844 Decimal expansion of greatest x having x^2+2x=2*cos(x).
%C A197844 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A197844 least x: -1.77323215749171672703899464197081641...
%e A197844 greatest x: 0.620762336586614714452120247321515...
%t A197844 a = 1; b = 2; c = 2;
%t A197844 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A197844 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A197844 r1 = x /. FindRoot[f[x] == g[x], {x, -1.8, -1.7}, WorkingPrecision -> 110]
%t A197844 RealDigits[r1] (* A197843 *)
%t A197844 r2 = x /. FindRoot[f[x] == g[x], {x, .62, .63}, WorkingPrecision -> 110]
%t A197844 RealDigits[r2] (* A197844 *)
%Y A197844 Cf. A197737.
%K A197844 nonn,cons
%O A197844 0,1
%A A197844 _Clark Kimberling_, Oct 20 2011