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 A198144 #6 Feb 07 2025 16:44:05
%S A198144 6,9,6,5,8,5,8,4,7,7,7,9,0,6,5,8,0,1,9,8,6,5,9,2,4,3,4,6,3,2,7,5,4,3,
%T A198144 5,8,8,5,5,9,0,0,5,4,6,0,3,5,9,3,5,5,5,7,7,8,4,6,5,4,9,7,8,7,6,5,8,8,
%U A198144 3,8,9,3,3,9,9,4,9,1,0,8,6,8,4,8,8,2,3,0,7,8,6,1,8,6,4,0,5,7,1
%N A198144 Decimal expansion of least x having x^2-4x=-3*cos(x).
%C A198144 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198144 least x: 0.69658584777906580198659243463275435885...
%e A198144 greatest x: 4.28804762370313657874580002787893697...
%t A198144 a = 1; b = -4; c = -3;
%t A198144 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198144 Plot[{f[x], g[x]}, {x, -1, 5}]
%t A198144 r1 = x /. FindRoot[f[x] == g[x], {x, 0.69, 0.70}, WorkingPrecision -> 110]
%t A198144 RealDigits[r1] (* A198144 *)
%t A198144 r2 = x /. FindRoot[f[x] == g[x], {x, 4.28, 4.29}, WorkingPrecision -> 110]
%t A198144 RealDigits[r2] (* A198145 *)
%Y A198144 Cf. A197737.
%K A198144 nonn,cons
%O A198144 0,1
%A A198144 _Clark Kimberling_, Oct 21 2011