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 A199787 #8 Feb 08 2025 22:30:24
%S A199787 1,2,8,1,9,0,5,4,7,3,9,8,3,4,0,5,3,7,7,3,8,4,5,5,4,8,5,6,8,3,4,7,5,8,
%T A199787 5,2,2,4,3,9,7,4,4,3,0,2,8,9,4,1,7,5,2,9,5,4,5,5,4,6,3,7,5,6,6,6,9,7,
%U A199787 1,1,2,7,7,7,3,4,3,9,8,3,9,6,7,1,8,8,3,5,4,6,8,5,6,6,5,0,4,3,7
%N A199787 Decimal expansion of x>0 satisfying 3*x^2-3*x*cos(x)=4*sin(x).
%C A199787 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199787 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199787 1.28190547398340537738455485683475852243974430...
%t A199787 a = 3; b = -3; c = 4;
%t A199787 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199787 Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}]
%t A199787 r = x /. FindRoot[f[x] == g[x], {x, 1.28, 1.29}, WorkingPrecision -> 110]
%t A199787 RealDigits[r] (* A199787 *)
%Y A199787 Cf. A199597.
%K A199787 nonn,cons
%O A199787 1,2
%A A199787 _Clark Kimberling_, Nov 10 2011