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 A199742 #13 Feb 08 2025 22:32:51
%S A199742 7,9,7,7,7,5,5,9,3,3,0,1,3,9,6,5,6,4,7,3,4,0,8,3,2,2,9,1,2,9,0,2,4,5,
%T A199742 4,4,4,1,8,4,2,8,9,4,1,3,6,1,8,0,6,2,5,8,3,6,2,8,4,6,0,1,5,1,1,2,9,9,
%U A199742 9,1,1,6,8,4,5,4,0,3,8,6,7,5,8,8,2,3,3,0,3,1,6,3,1,5,3,5,0,3,1
%N A199742 Decimal expansion of x>0 satisfying 2*x^2-x*cos(x)=sin(x).
%C A199742 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199742 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199742 0.797775593301396564734083229129024544418428941...
%t A199742 a = 2; b = -1; c = 1;
%t A199742 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199742 Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}]
%t A199742 r = x /. FindRoot[f[x] == g[x], {x, .79, .80}, WorkingPrecision -> 110]
%t A199742 RealDigits[r] (* A199742 *)
%Y A199742 Cf. A199597.
%K A199742 nonn,cons
%O A199742 0,1
%A A199742 _Clark Kimberling_, Nov 10 2011
%E A199742 Name corrected by _Sean A. Irvine_, Jan 12 2025