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 A200005 #13 Feb 12 2025 04:49:11
%S A200005 1,3,6,0,8,3,2,2,5,5,3,9,0,6,6,8,9,0,4,6,7,1,8,3,9,2,8,5,6,9,1,3,2,6,
%T A200005 3,6,8,8,2,5,4,9,7,9,2,6,2,5,5,0,8,5,8,3,1,1,0,7,4,1,3,2,6,7,8,2,0,6,
%U A200005 1,0,6,2,3,0,1,3,9,9,4,2,4,7,4,6,2,9,0,5,6,4,0,9,9,1,4,8,2,9,9
%N A200005 Decimal expansion of greatest x satisfying 2*x^2 + cos(x) = 4*sin(x).
%C A200005 See A199949 for a guide to related sequences. The Mathematica program includes a graph.
%H A200005 G. C. Greubel, <a href="/A200005/b200005.txt">Table of n, a(n) for n = 1..10000</a>
%H A200005 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A200005 least x: 0.2841554251771481491680536288735443310...
%e A200005 greatest x: 1.36083225539066890467183928569132636...
%t A200005 a = 2; b = 1; c = 4;
%t A200005 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c*Sin[x]
%t A200005 Plot[{f[x], g[x]}, {x, -.1, 2}, {AxesOrigin -> {0, 0}}]
%t A200005 r = x /. FindRoot[f[x] == g[x], {x, .28, .29}, WorkingPrecision -> 110]
%t A200005 RealDigits[r] (* A200004 *)
%t A200005 r = x /. FindRoot[f[x] == g[x], {x, 1.3, 1.4}, WorkingPrecision -> 110]
%t A200005 RealDigits[r] (* A200005 *)
%o A200005 (PARI) a=2; b=1; c=4; solve(x=1, 2, a*x^2 + b*cos(x) - c*sin(x)) \\ _G. C. Greubel_, Jun 23 2018
%Y A200005 Cf. A199949.
%K A200005 nonn,cons
%O A200005 1,2
%A A200005 _Clark Kimberling_, Nov 12 2011