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 A197335 #11 Feb 16 2025 05:24:11
%S A197335 3,0,9,9,8,1,4,8,9,0,7,0,1,3,6,9,1,0,3,1,8,0,1,6,2,2,6,8,6,0,1,8,7,1,
%T A197335 9,4,6,5,0,1,4,6,2,3,5,1,1,5,7,2,9,0,4,4,3,3,8,1,7,2,9,0,6,4,4,5,5,3,
%U A197335 0,9,9,9,2,5,5,3,2,3,6,5,3,2,4,1,2,1,5,3,3,6,4,8,5,9,6,7,7,2,8
%N A197335 Decimal expansion of least x > 0 having cos(x) = cos(3*Pi*x)^2.
%C A197335 The Mathematica program includes a graph. See A197476 for a guide for the least x > 0 satisfying cos(b*x) = cos(c*x)^2 for selected b and c.
%C A197335 This number is irrational. I cannot prove it to be algebraic or transcendental. - _Charles R Greathouse IV_, Feb 16 2025
%e A197335 0.309981489070136910318016226860187194650...
%t A197335 b = 1; c = 3 Pi; f[x_] := Cos[x]
%t A197335 t = x /. FindRoot[f[b*x] == f[c*x]^2, {x, 3, .31}, WorkingPrecision -> 110]
%t A197335 RealDigits[t] (* A197335 *)
%t A197335 Plot[{f[b*x], f[c*x]^2}, {x, 0, Pi/4}]
%Y A197335 Cf. A197476.
%K A197335 nonn,cons
%O A197335 0,1
%A A197335 _Clark Kimberling_, Oct 15 2011