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 A199865 #8 Feb 08 2025 22:37:22
%S A199865 4,6,4,6,0,2,5,2,5,9,9,5,2,3,9,3,9,5,8,9,2,1,9,0,6,0,0,7,5,7,4,7,8,4,
%T A199865 6,4,3,5,4,0,5,6,5,2,4,3,5,7,0,5,0,2,4,8,6,1,3,2,1,3,0,6,1,0,9,7,7,8,
%U A199865 5,0,3,0,3,1,9,6,4,9,1,5,8,1,1,7,1,9,4,5,2,3,6,3,7,3,3,9,1,6,5
%N A199865 Decimal expansion of x>0 satisfying 4*x^2-x*cos(x)=sin(x).
%C A199865 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199865 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199865 0.4646025259952393958921906007574784643540565243570...
%t A199865 a = 4; b = -1; c = 1;
%t A199865 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199865 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A199865 r = x /. FindRoot[f[x] == g[x], {x, .46, .47}, WorkingPrecision -> 110]
%t A199865 RealDigits[r] (* A199865 *)
%Y A199865 Cf. A199597.
%K A199865 nonn,cons
%O A199865 0,1
%A A199865 _Clark Kimberling_, Nov 11 2011