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 A197583 #22 Feb 16 2025 05:40:00
%S A197583 1,1,2,0,9,1,5,6,8,2,2,5,4,8,5,4,3,0,3,2,2,1,5,9,3,7,5,8,1,3,6,7,9,9,
%T A197583 1,4,6,0,1,0,3,2,2,9,2,7,9,4,7,9,5,2,3,2,6,5,8,5,6,6,5,4,7,5,0,8,3,2,
%U A197583 7,1,8,0,2,5,9,3,1,2,4,6,5,7,7,6,0,7,9,6,9
%N A197583 Decimal expansion of least x > 0 having cos(Pi*x/3) = (cos(2*x))^2.
%C A197583 This number is irrational. I cannot prove it to be algebraic or transcendental. - _Charles R Greathouse IV_, Feb 16 2025
%e A197583 1.120915682254854303221593758136799146010322927947952326585665475083271...
%p A197583 Digits := 100 ; fsolve( cos(Pi*x/3)-(cos(2*x))^2,x=0.1..1.4) ; # _R. J. Mathar_, Oct 18 2011
%t A197583 RealDigits[x/.FindRoot[Cos[Pi x/3]==(Cos[2x])^2,{x,1},WorkingPrecision-> 100]][[1]] (* _Harvey P. Dale_, Apr 08 2015 *)
%o A197583 (PARI) solve(x=1,2,cos(Pi/3*x)-cos(x+x)^2) \\ _Charles R Greathouse IV_, Oct 18 2011
%Y A197583 Cf. A197133.
%K A197583 nonn,cons
%O A197583 1,3
%A A197583 _Clark Kimberling_, Oct 16 2011
%E A197583 Corrected by _Charles R Greathouse IV_, Oct 18 2011