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 A198609 #9 Apr 23 2025 12:49:26
%S A198609 5,4,9,5,8,5,9,7,7,0,0,5,8,3,2,3,3,1,6,7,8,5,3,6,9,2,1,1,2,6,3,7,1,7,
%T A198609 8,0,2,5,8,9,5,9,1,0,5,8,0,0,3,5,1,8,1,3,8,5,3,4,4,5,0,4,0,8,6,1,5,9,
%U A198609 7,3,0,9,1,8,9,0,2,8,7,8,8,2,6,8,6,0,9,9,7,2,1,9,3,5,2,4,1,7,5
%N A198609 Decimal expansion of -x where x<0 satisfies 2*x^2+3x=2*sin(x).
%C A198609 See A198414 for a guide to related sequences. The Mathematica program includes a graph.
%H A198609 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198609 -0.54958597700583233167853692112637178025895...
%t A198609 a = 2; b = 3; c = 2;
%t A198609 f[x_] := a*x^2 + b*x; g[x_] := c*Sin[x]
%t A198609 Plot[{f[x], g[x]}, {x, -1, .2}]
%t A198609 r = x /. FindRoot[f[x] == g[x], {x, -.55, -.54}, WorkingPrecision -> 110]
%t A198609 RealDigits[r] (* A198609 *)
%Y A198609 Cf. A198414.
%K A198609 nonn,cons
%O A198609 0,1
%A A198609 _Clark Kimberling_, Oct 27 2011