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 A199863 #8 Feb 08 2025 22:37:27
%S A199863 8,3,4,0,0,6,7,4,4,6,4,2,9,0,8,3,3,9,1,1,1,0,1,6,6,8,2,9,0,7,9,2,2,4,
%T A199863 5,8,5,5,8,6,5,0,2,6,5,9,9,1,8,1,0,4,8,5,1,0,1,7,6,7,6,2,6,1,7,5,6,3,
%U A199863 2,1,7,1,7,9,8,2,7,1,1,8,3,0,9,3,5,3,7,3,8,8,2,2,5,0,0,8,5,5,5
%N A199863 Decimal expansion of x>0 satisfying 4*x^2-x*cos(x)=3*sin(x).
%C A199863 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199863 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199863 0.8340067446429083391110166829079224585586502659...
%t A199863 a = 4; b = -1; c = 3;
%t A199863 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199863 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A199863 r = x /. FindRoot[f[x] == g[x], {x, .83, .84}, WorkingPrecision -> 110]
%t A199863 RealDigits[r] (* A199863 *)
%Y A199863 Cf. A199597.
%K A199863 nonn,cons
%O A199863 0,1
%A A199863 _Clark Kimberling_, Nov 11 2011