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 A198100 #6 Feb 07 2025 16:44:04
%S A198100 5,0,1,3,0,4,7,5,5,4,5,4,8,0,6,4,6,3,3,9,3,6,9,0,3,5,7,5,6,8,1,9,8,1,
%T A198100 3,0,5,5,2,3,4,5,1,0,1,0,8,2,1,5,0,5,7,8,0,8,6,0,2,6,4,3,5,1,2,3,4,9,
%U A198100 8,6,8,7,4,5,2,9,4,4,8,4,5,0,2,3,6,7,8,7,3,8,1,8,7,6,3,6,1,3,6
%N A198100 Decimal expansion of least x having x^2-4x=-2*cos(x).
%C A198100 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198100 least x: 0.50130475545480646339369035756819...
%e A198100 greatest x: 4.222749528794927324484249676610...
%t A198100 a = 1; b = -4; c = -2;
%t A198100 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198100 Plot[{f[x], g[x]}, {x, 0, 5}]
%t A198100 r1 = x /. FindRoot[f[x] == g[x], {x, .5, .51}, WorkingPrecision -> 110]
%t A198100 RealDigits[r1] (* A198100 *)
%t A198100 r2 = x /. FindRoot[f[x] == g[x], {x, 4.2, 4.3}, WorkingPrecision -> 110]
%t A198100 RealDigits[r2] (* A198101 *)
%Y A198100 Cf. A197737.
%K A198100 nonn,cons
%O A198100 0,1
%A A198100 _Clark Kimberling_, Oct 21 2011