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 A198230 #6 Feb 07 2025 16:44:05
%S A198230 1,1,2,6,9,9,6,5,9,6,1,1,1,3,9,9,6,5,8,3,4,5,2,3,7,3,8,4,3,2,5,4,0,4,
%T A198230 8,5,4,9,3,7,7,7,1,3,8,6,4,4,6,8,9,1,7,0,7,6,6,3,8,2,1,6,3,8,9,7,3,2,
%U A198230 5,0,6,1,3,0,0,6,9,5,4,3,3,5,9,8,1,1,2,2,2,6,6,1,7,3,1,2,1,7,5
%N A198230 Decimal expansion of least x having 3*x^2+3x=cos(x).
%C A198230 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198230 least x: -1.126996596111399658345237384325404854...
%e A198230 greatest x: 0.2565849342235694401504579474990935...
%t A198230 a = 3; b = 3; c = 1;
%t A198230 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198230 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198230 r1 = x /. FindRoot[f[x] == g[x], {x, -1.2, -1.1}, WorkingPrecision -> 110]
%t A198230 RealDigits[r1] (* A198230 *)
%t A198230 r2 = x /. FindRoot[f[x] == g[x], {x, .25, .26}, WorkingPrecision -> 110]
%t A198230 RealDigits[r2] (* A198231 *)
%Y A198230 Cf. A197737.
%K A198230 nonn,cons
%O A198230 1,3
%A A198230 _Clark Kimberling_, Oct 23 2011