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 A198105 #6 Feb 07 2025 16:44:04
%S A198105 5,0,1,0,4,1,1,8,6,4,4,6,4,9,0,3,8,3,3,1,5,1,4,1,7,7,9,0,6,6,3,4,6,4,
%T A198105 9,7,8,6,0,8,4,9,9,1,4,5,4,4,5,0,9,0,6,7,8,0,4,3,2,0,5,8,4,4,4,6,2,6,
%U A198105 3,3,0,2,7,0,5,5,2,4,7,0,5,3,4,5,8,4,0,1,6,9,4,5,2,2,4,9,1,2,8
%N A198105 Decimal expansion of greatest x having x^2+3x=2*cos(x).
%C A198105 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198105 least x: -2.38894934360890459687043267819730...
%e A198105 greatest x: 0.5010411864464903833151417790663...
%t A198105 a = 1; b = 3; c = 2;
%t A198105 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198105 Plot[{f[x], g[x]}, {x, -3, 1}]
%t A198105 r1 = x /. FindRoot[f[x] == g[x], {x, -2.4, -2.3}, WorkingPrecision -> 110]
%t A198105 RealDigits[r1] (* A198104 *)
%t A198105 r2 = x /. FindRoot[f[x] == g[x], {x, .5, .51}, WorkingPrecision -> 110]
%t A198105 RealDigits[r2] (* A198105 *)
%Y A198105 Cf. A197737.
%K A198105 nonn,cons
%O A198105 0,1
%A A198105 _Clark Kimberling_, Oct 21 2011