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 A199967 #18 Feb 12 2025 04:48:29
%S A199967 4,5,0,4,1,2,2,3,6,3,8,3,2,4,9,1,3,3,7,6,4,7,8,1,9,0,7,8,3,8,3,9,7,7,
%T A199967 8,4,1,7,1,6,1,9,0,7,4,6,3,2,2,9,7,3,5,9,9,9,4,0,9,3,4,8,3,9,5,8,0,6,
%U A199967 3,6,2,8,3,9,7,8,0,8,5,2,8,5,8,6,5,1,7,2,8,8,8,2,1,7,7,4,9,0,2
%N A199967 Decimal expansion of least x satisfying 2*x^2 + cos(x) = 3*sin(x).
%C A199967 See A199949 for a guide to related sequences. The Mathematica program includes a graph.
%H A199967 G. C. Greubel, <a href="/A199967/b199967.txt">Table of n, a(n) for n = 0..10000</a>
%H A199967 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199967 least x: 0.45041223638324913376478190783839778...
%e A199967 greatest x: 0.989450014493949167489788332695714...
%t A199967 a = 2; b = 1; c = 3;
%t A199967 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c*Sin[x]
%t A199967 Plot[{f[x], g[x]}, {x, -.1, 2}, {AxesOrigin -> {0, 0}}]
%t A199967 r = x /. FindRoot[f[x] == g[x], {x, .4, .5}, WorkingPrecision -> 110]
%t A199967 RealDigits[r] (* A199967 *)
%t A199967 r = x /. FindRoot[f[x] == g[x], {x, .98, .99}, WorkingPrecision -> 110]
%t A199967 RealDigits[r] (* A200003 *)
%o A199967 (PARI) a=2; b=1; c=3; solve(x=0, .5, a*x^2 + b*cos(x) - c*sin(x)) \\ _G. C. Greubel_, Jun 23 2018
%Y A199967 Cf. A199949.
%K A199967 nonn,cons
%O A199967 0,1
%A A199967 _Clark Kimberling_, Nov 12 2011
%E A199967 A-number corrected by _Jaroslav Krizek_, Nov 27 2011