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 A201399 #10 Jan 30 2025 15:32:46
%S A201399 1,4,0,2,4,0,6,0,3,1,2,7,6,5,1,6,4,7,2,8,6,3,7,6,5,8,5,4,6,9,3,9,7,3,
%T A201399 0,3,2,3,0,5,2,3,1,8,9,3,8,7,0,0,8,1,0,9,3,8,2,9,8,9,9,6,6,5,5,8,2,5,
%U A201399 2,7,7,7,8,3,4,2,4,3,5,0,8,4,7,5,7,8,1,8,5,1,9,3,9,3,4,9,5,5,5
%N A201399 Decimal expansion of x satisfying x^2 + 4 = sec(x) and 0 < x < Pi.
%C A201399 See A201397 for a guide to related sequences. The Mathematica program includes a graph.
%H A201399 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A201399 1.40240603127651647286376585469397303230523...
%t A201399 a = 1; c = 4;
%t A201399 f[x_] := a*x^2 + c; g[x_] := Sec[x]
%t A201399 Plot[{f[x], g[x]}, {x, 0, Pi}, {AxesOrigin -> {0, 0}}]
%t A201399 r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]
%t A201399 RealDigits[r] (* A201399 *)
%Y A201399 Cf. A201397.
%K A201399 nonn,cons
%O A201399 1,2
%A A201399 _Clark Kimberling_, Dec 01 2011