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 A198113 #6 Feb 07 2025 16:44:04
%S A198113 4,6,3,9,0,2,3,8,2,5,9,7,4,1,1,9,0,9,7,5,6,7,0,3,1,6,9,5,3,5,3,5,0,5,
%T A198113 8,9,7,2,0,7,5,7,5,8,2,7,1,2,0,1,4,2,0,1,5,3,6,2,2,5,6,8,9,2,6,5,2,5,
%U A198113 9,5,3,1,9,5,9,9,6,0,9,6,9,0,7,4,0,1,1,9,4,4,2,7,3,8,0,3,6,9,7
%N A198113 Decimal expansion of greatest x having 2*x^2+x=cos(x).
%C A198113 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198113 least x: -0.870316341177487538672405292348150615...
%e A198113 greatest x: 0.463902382597411909756703169535350589...
%t A198113 a = 2; b = 1; c = 1;
%t A198113 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198113 Plot[{f[x], g[x]}, {x, -1, 1}]
%t A198113 r1 = x /. FindRoot[f[x] == g[x], {x, -0.88, -0.87}, WorkingPrecision -> 110]
%t A198113 RealDigits[r1](* A198112 *)
%t A198113 r2 = x /.FindRoot[f[x] == g[x], {x, 4.6, 4.7}, WorkingPrecision -> 110]
%t A198113 RealDigits[r2](* A198113 *)
%Y A198113 Cf. A197737.
%K A198113 nonn,cons
%O A198113 0,1
%A A198113 _Clark Kimberling_, Oct 21 2011