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 A199730 #8 Feb 08 2025 22:24:50
%S A199730 1,3,5,6,9,2,0,0,6,2,3,6,1,3,7,1,8,4,4,2,2,5,1,0,3,4,8,6,3,3,7,3,9,6,
%T A199730 5,4,6,2,4,7,3,4,9,1,7,2,6,7,2,4,4,4,8,6,3,3,6,7,0,9,2,9,2,5,2,1,6,1,
%U A199730 5,6,1,8,7,2,8,0,4,4,8,2,8,9,4,3,7,5,7,3,7,2,4,8,0,7,5,1,2,9,3
%N A199730 Decimal expansion of x>0 satisfying x^2-3*x*cos(x)=sin(x).
%C A199730 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199730 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199730 1.3569200623613718442251034863373965462473491...
%t A199730 a = 1; b = -3; c = 1;
%t A199730 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199730 Plot[{f[x], g[x]}, {x, -2 Pi, Pi}, {AxesOrigin -> {0, 0}}]
%t A199730 r = x /. FindRoot[f[x] == g[x], {x, 1.35, 1.36}, WorkingPrecision -> 110]
%t A199730 RealDigits[r] (* A199730 *)
%Y A199730 Cf. A199597.
%K A199730 nonn,cons
%O A199730 1,2
%A A199730 _Clark Kimberling_, Nov 09 2011