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 A198352 #6 Feb 07 2025 16:44:05
%S A198352 5,4,1,4,1,8,9,0,3,1,7,2,9,0,6,7,1,1,2,9,6,9,2,1,9,6,7,2,0,6,2,4,0,6,
%T A198352 8,8,1,3,3,0,1,8,0,6,2,4,3,1,5,2,0,5,6,5,0,4,8,8,9,6,6,8,2,9,7,8,2,6,
%U A198352 1,4,2,2,3,2,8,8,0,0,0,9,7,6,7,7,5,3,2,3,7,8,4,3,1,9,8,9,3,9,1
%N A198352 Decimal expansion of greatest x having 4*x^2+x=2*cos(x).
%C A198352 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198352 least x: -0.74421989852706246873275828006370...
%e A198352 greatest x: 0.541418903172906711296921967206240...
%t A198352 a = 4; b = 1; c = 2;
%t A198352 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198352 Plot[{f[x], g[x]}, {x, -1, 1}]
%t A198352 r1 = x /. FindRoot[f[x] == g[x], {x, -.8, -.7}, WorkingPrecision -> 110]
%t A198352 RealDigits[r1] (* A198351 *)
%t A198352 r2 = x /. FindRoot[f[x] == g[x], {x, .5, .6}, WorkingPrecision -> 110]
%t A198352 RealDigits[r2] (* A198352 *)
%Y A198352 Cf. A197737.
%K A198352 nonn,cons
%O A198352 0,1
%A A198352 _Clark Kimberling_, Oct 23 2011