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 A199778 #8 Feb 08 2025 22:32:42
%S A199778 1,3,7,0,6,8,0,9,7,2,6,0,4,8,9,3,4,8,5,7,9,1,1,2,0,8,0,6,8,8,0,2,9,0,
%T A199778 4,3,2,9,8,3,6,4,6,0,2,7,1,3,0,0,5,1,0,3,9,5,0,8,9,7,8,5,0,7,0,4,2,4,
%U A199778 5,6,7,8,3,5,4,6,2,7,6,4,3,4,1,4,5,8,4,8,6,1,9,2,2,1,7,3,3,1,3
%N A199778 Decimal expansion of x>0 satisfying 2*x^2-3*x*cos(x)=3*sin(x).
%C A199778 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199778 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199778 1.370680972604893485791120806880290432983646027...
%t A199778 a = 2; b = -3; c = 3;
%t A199778 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199778 Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}]
%t A199778 r = x /. FindRoot[f[x] == g[x], {x, 1.37, 1.38}, WorkingPrecision -> 110]
%t A199778 RealDigits[r] (* A199778 *)
%Y A199778 Cf. A199597.
%K A199778 nonn,cons
%O A199778 1,2
%A A199778 _Clark Kimberling_, Nov 10 2011