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 A198419 #8 Feb 07 2025 16:44:05
%S A198419 1,5,6,1,5,1,0,9,9,1,0,7,4,2,6,9,1,2,1,8,7,3,6,8,3,2,0,7,3,7,6,9,5,2,
%T A198419 3,2,9,2,1,5,3,4,1,6,4,4,9,4,0,3,0,7,9,1,6,9,4,8,1,2,6,9,6,6,1,9,2,4,
%U A198419 0,2,3,0,2,1,1,8,4,8,1,0,8,5,4,8,5,7,0,4,9,4,0,4,8,4,2,0,6,7,5
%N A198419 Decimal expansion of x>0 having x^2+x=4*sin(x).
%C A198419 See A198414 for a guide to related sequences. The Mathematica program includes a graph.
%H A198419 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198419 1.561510991074269121873683207376952329215...
%t A198419 a = 1; b = 1; c = 4;
%t A198419 f[x_] := a*x^2 + b*x; g[x_] := c*Sin[x]
%t A198419 Plot[{f[x], g[x]}, {x, -1, 2}]
%t A198419 r = x /. FindRoot[f[x] == g[x], {x, 1.56, 1.57}, WorkingPrecision -> 110]
%t A198419 RealDigits[r] (* A198419 *)
%o A198419 (PARI) solve(x=1,2, x^2+x-4*sin(x)) \\ _Charles R Greathouse IV_, Jan 28 2025
%Y A198419 Cf. A198414.
%K A198419 nonn,cons
%O A198419 1,2
%A A198419 _Clark Kimberling_, Oct 24 2011