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 A199669 #8 Feb 08 2025 22:26:56
%S A199669 7,1,9,8,5,9,8,6,7,2,0,4,1,1,7,6,4,9,3,6,1,1,3,3,4,4,0,9,1,0,7,0,0,9,
%T A199669 5,3,2,3,1,1,8,6,0,3,7,4,7,5,9,5,9,4,6,2,6,8,9,8,0,2,9,4,6,0,8,9,6,0,
%U A199669 5,8,6,9,6,8,7,8,1,5,3,9,7,6,4,6,5,0,5,2,2,5,9,0,1,5,4,3,0,8,9
%N A199669 Decimal expansion of x>0 satisfying 3*x^2+2*x*cos(x)=4*sin(x).
%C A199669 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199669 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199669 0.7198598672041176493611334409107009532311...
%t A199669 a = 3; b = 2; c = 4;
%t A199669 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199669 Plot[{f[x], g[x]}, {x, -1, 1}, {AxesOrigin -> {0, 0}}]
%t A199669 r = x /. FindRoot[f[x] == g[x], {x, .71, .72}, WorkingPrecision -> 110]
%t A199669 RealDigits[r] (* A199669 *)
%Y A199669 Cf. A199597.
%K A199669 nonn,cons
%O A199669 0,1
%A A199669 _Clark Kimberling_, Nov 09 2011