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 A198240 #6 Feb 07 2025 16:44:05
%S A198240 1,4,3,0,8,3,3,4,2,0,7,1,7,7,2,8,5,4,2,5,6,6,5,4,3,9,3,3,6,3,9,1,3,8,
%T A198240 8,5,9,9,0,2,1,8,3,5,9,2,1,4,8,4,4,4,7,5,8,6,5,1,2,9,3,6,0,4,8,3,7,1,
%U A198240 3,3,8,0,5,4,1,2,3,2,2,6,5,7,9,2,4,5,7,1,3,4,4,7,6,3,9,6,1,1,3
%N A198240 Decimal expansion of least x having 3*x^2+4x=3*cos(x).
%C A198240 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198240 least x: -1.4308334207177285425665439336391388599...
%e A198240 greatest x: 0.48600443599229304081619898150357856...
%t A198240 a = 3; b = 4; c = 3;
%t A198240 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198240 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198240 r1 = x /. FindRoot[f[x] == g[x], {x, -1.5, -1.4}, WorkingPrecision -> 110]
%t A198240 RealDigits[r1](* A198240 *)
%t A198240 r2 = x /. FindRoot[f[x] == g[x], {x, .48, .49}, WorkingPrecision -> 110]
%t A198240 RealDigits[r2] (* A198241 *)
%Y A198240 Cf. A197737.
%K A198240 nonn,cons
%O A198240 1,2
%A A198240 _Clark Kimberling_, Oct 23 2011