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 A198140 #7 Feb 07 2025 16:44:05
%S A198140 1,2,5,3,6,1,0,6,2,9,1,6,6,5,3,9,5,8,6,3,0,7,8,4,2,4,6,6,9,4,5,2,8,3,
%T A198140 6,2,9,0,4,8,3,2,4,7,5,0,4,3,8,3,7,1,0,9,8,0,1,6,4,0,4,1,5,6,2,6,9,3,
%U A198140 3,9,6,8,3,2,5,3,3,8,1,0,4,3,4,3,6,1,8,3,7,6,4,0,4,0,0,9,1,3,8
%N A198140 Decimal expansion of least x having x^2-2x=-3*cos(x). Decimal expansion of greatest x having x^2-2x=-3*cos(x).
%C A198140 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198140 least x: 1.25361062916653958630784246694528362...
%e A198140 greatest x: 2.99155642389786356257272264824822031...
%t A198140 a = 1; b = -2; c = -3;
%t A198140 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198140 Plot[{f[x], g[x]}, {x, -1, 4}]
%t A198140 r1 = x /. FindRoot[f[x] == g[x], {x, 1.25, 1.26}, WorkingPrecision -> 110]
%t A198140 RealDigits[r1] (* A198140 *)
%t A198140 r2 = x /. FindRoot[f[x] == g[x], {x, 2.9, 3.0}, WorkingPrecision -> 110]
%t A198140 RealDigits[r2] (* A198141 *)
%Y A198140 Cf. A197737.
%K A198140 nonn,cons
%O A198140 1,2
%A A198140 _Clark Kimberling_, Oct 21 2011