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 A198228 #7 Feb 07 2025 16:44:05
%S A198228 1,1,4,6,0,6,9,5,8,0,2,1,0,4,4,1,8,1,3,3,9,4,3,5,1,1,9,5,7,8,0,6,1,1,
%T A198228 8,3,1,9,6,9,7,1,2,7,5,0,3,5,7,5,4,0,7,7,1,5,5,7,0,1,3,0,4,9,3,6,2,3,
%U A198228 7,0,6,6,8,2,1,7,8,2,2,1,5,8,2,5,7,1,7,2,9,2,4,0,2,2,2,0,1,4,1
%N A198228 Decimal expansion of least x having 3*x^2+2x=4*cos(x).
%C A198228 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198228 least x: -1.146069580210441813394351195780611...
%e A198228 greatest x: 0.721341307648015582421031722872306448...
%t A198228 a = 3; b = 2; c = 4;
%t A198228 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198228 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198228 r1 = x /. FindRoot[f[x] == g[x], {x, -1.2, -1.1}, WorkingPrecision -> 110]
%t A198228 RealDigits[r1] (* A198228 *)
%t A198228 r2 = x /. FindRoot[f[x] == g[x], {x, .72, .73}, WorkingPrecision -> 110]
%t A198228 RealDigits[r2] (* A198229 *)
%Y A198228 Cf. A197737.
%K A198228 nonn,cons
%O A198228 1,3
%A A198228 _Clark Kimberling_, Oct 23 2011