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 A198122 #8 Feb 07 2025 16:44:04
%S A198122 2,7,9,3,2,0,7,7,9,7,3,8,1,6,5,0,6,1,2,8,0,5,9,3,3,9,6,6,5,5,3,9,5,5,
%T A198122 4,5,6,2,2,7,5,8,0,0,4,5,9,7,1,7,5,0,7,1,9,7,1,5,7,2,0,3,7,7,8,7,0,6,
%U A198122 0,4,7,5,9,8,5,5,1,2,1,8,5,0,0,8,7,8,8,7,2,7,1,1,6,6,8,8,2,8,9,7,5
%N A198122 Decimal expansion of least x having 2*x^2-4x=-cos(x).
%C A198122 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198122 least x: 0.27932077973816506128059339665539554...
%e A198122 greatest x: 2.123633334519982394198770246411061...
%t A198122 a = 2; b = -4; c = -1;
%t A198122 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198122 Plot[{f[x], g[x]}, {x, -1, 3}]
%t A198122 r1 = x /. FindRoot[f[x] == g[x], {x, .27, .28}, WorkingPrecision -> 110]
%t A198122 RealDigits[r1](* A198122 *)
%t A198122 r2 = x /. FindRoot[f[x] == g[x], {x, 2.1, 2.2}, WorkingPrecision -> 110]
%t A198122 RealDigits[r2](* A198123 *)
%Y A198122 Cf. A197737.
%K A198122 nonn,cons
%O A198122 0,1
%A A198122 _Clark Kimberling_, Oct 21 2011