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 A199723 #8 Feb 08 2025 22:24:36
%S A199723 1,7,8,0,6,0,8,1,1,9,9,6,6,6,3,5,2,0,4,3,3,7,8,0,1,8,4,9,0,7,6,6,6,6,
%T A199723 9,2,2,1,7,0,4,2,1,7,2,5,7,3,1,8,2,1,6,4,4,5,0,6,1,2,5,1,4,5,5,7,4,8,
%U A199723 0,4,1,0,5,0,9,3,6,1,6,8,3,3,2,8,5,0,1,3,2,4,6,4,7,8,4,6,5,9,5
%N A199723 Decimal expansion of x>0 satisfying x^2-2*x*cos(x)=4*sin(x).
%C A199723 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199723 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199723 1.780608119966635204337801849076666...
%t A199723 a = 1; b = -2; c = 4;
%t A199723 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199723 Plot[{f[x], g[x]}, {x, -2 Pi, Pi}, {AxesOrigin -> {0, 0}}]
%t A199723 r = x /. FindRoot[f[x] == g[x], {x, 1.78, 1.79}, WorkingPrecision -> 110]
%t A199723 RealDigits[r] (* A199723 *)
%Y A199723 Cf. A199597.
%K A199723 nonn,cons
%O A199723 1,2
%A A199723 _Clark Kimberling_, Nov 09 2011