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 A199600 #8 Feb 08 2025 13:26:51
%S A199600 6,5,5,5,3,8,2,9,9,5,3,9,6,9,4,5,0,7,1,8,5,8,6,6,2,4,6,3,4,3,9,9,3,0,
%T A199600 7,3,9,2,4,2,1,1,6,4,8,9,3,5,7,8,0,4,1,0,7,7,0,6,4,5,5,0,1,6,5,7,7,8,
%U A199600 0,5,4,3,6,1,0,6,4,1,7,4,5,9,5,2,4,0,1,1,8,4,7,9,0,9,2,2,0,9,1
%N A199600 Decimal expansion of x<0 satisfying x^2+2*x*cos(x)=sin(x).
%C A199600 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199600 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199600 -0.655538299539694507185866246343993073924211...
%t A199600 a = 1; b = 2; c = 1;
%t A199600 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199600 Plot[{f[x], g[x]}, {x, -Pi, Pi}, {AxesOrigin -> {0, 0}}]
%t A199600 r = x /. FindRoot[f[x] == g[x], {x, -.7, -.6}, WorkingPrecision -> 110]
%t A199600 RealDigits[r] (* A199600 *)
%Y A199600 Cf. A199597.
%K A199600 nonn,cons
%O A199600 0,1
%A A199600 _Clark Kimberling_, Nov 08 2011