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 A198822 #19 Feb 07 2025 16:34:13
%S A198822 1,4,7,8,1,7,0,2,6,6,4,3,0,3,2,1,2,8,3,3,1,0,6,2,4,1,7,5,3,4,7,7,4,6,
%T A198822 8,0,8,0,2,6,8,2,3,5,1,7,8,0,1,5,1,4,9,2,9,9,3,1,3,6,1,2,7,1,5,4,6,5,
%U A198822 6,9,3,0,9,7,6,7,0,9,5,1,8,9,1,9,8,7,5,2,2,1,3,8,6,3,5,3,3,0,6
%N A198822 Decimal expansion of x > 0 satisfying x^2 - 2*cos(x) = 2.
%C A198822 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198822 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%F A198822 Equals 2*A003957. - _Gleb Koloskov_, Jun 16 2021
%e A198822 1.47817026643032128331062417534774680802682351780...
%t A198822 a = 1; b = -2; c = 2;
%t A198822 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198822 Plot[{f[x], g[x]}, {x, -3, 3}, {AxesOrigin -> {0, 0}}]
%t A198822 r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]
%t A198822 RealDigits[r] (* A198822 *)
%o A198822 (PARI) solve(x=0,1,cos(x)-x)*2 \\ _Gleb Koloskov_, Jun 16 2021
%Y A198822 Cf. A003957, A198755.
%K A198822 nonn,cons
%O A198822 1,2
%A A198822 _Clark Kimberling_, Oct 30 2011