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 A201398 #10 Jan 30 2025 15:33:22
%S A201398 1,3,6,3,5,1,9,4,6,8,4,8,6,2,0,1,8,5,7,3,5,2,2,8,1,2,8,4,5,8,4,2,3,7,
%T A201398 8,7,7,3,2,9,5,1,4,4,9,4,6,3,1,2,5,9,4,4,8,5,3,8,7,8,9,0,6,1,7,8,7,4,
%U A201398 8,5,4,8,4,5,6,2,7,2,1,2,4,5,7,8,9,9,5,1,3,5,3,7,2,0,8,7,7,9,4
%N A201398 Decimal expansion of x satisfying x^2 + 3 = sec(x) and 0 < x < Pi.
%C A201398 See A201397 for a guide to related sequences. The Mathematica program includes a graph.
%H A201398 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A201398 1.363519468486201857352281284584237877...
%t A201398 a = 1; c = 3;
%t A201398 f[x_] := a*x^2 + c; g[x_] := Sec[x]
%t A201398 Plot[{f[x], g[x]}, {x, 0, Pi}, {AxesOrigin -> {0, 0}}]
%t A201398 r = x /. FindRoot[f[x] == g[x], {x, 1.3, 1.4}, WorkingPrecision -> 110]
%t A201398 RealDigits[r] (* A201398 *)
%Y A201398 Cf. A201397.
%K A201398 nonn,cons
%O A201398 1,2
%A A201398 _Clark Kimberling_, Dec 01 2011