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 A199724 #8 Feb 08 2025 22:24:37
%S A199724 1,6,5,1,0,0,0,9,3,4,4,3,9,7,1,5,7,9,8,3,0,6,8,4,8,0,8,9,8,0,4,5,7,2,
%T A199724 8,1,4,4,1,5,8,2,8,5,5,2,9,2,4,1,7,7,2,2,7,0,8,0,6,8,6,3,4,0,5,3,0,3,
%U A199724 9,3,7,2,0,6,4,5,5,1,8,9,7,0,1,0,4,9,1,3,7,3,7,4,0,8,3,2,9,1,8
%N A199724 Decimal expansion of x>0 satisfying x^2-2*x*cos(x)=3*sin(x).
%C A199724 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199724 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199724 1.651000934439715798306848089804572814415828...
%t A199724 a = 1; b = -2; c = 3;
%t A199724 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199724 Plot[{f[x], g[x]}, {x, -2 Pi, Pi}, {AxesOrigin -> {0, 0}}]
%t A199724 r = x /. FindRoot[f[x] == g[x], {x, 1.65, 1.66}, WorkingPrecision -> 110]
%t A199724 RealDigits[r] (* A199724 *)
%Y A199724 Cf. A199597.
%K A199724 nonn,cons
%O A199724 1,2
%A A199724 _Clark Kimberling_, Nov 09 2011