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 A201283 #10 Jan 30 2025 15:45:50
%S A201283 2,4,1,5,9,1,8,5,7,4,3,6,4,5,3,6,4,5,3,7,0,5,0,7,5,8,4,3,5,7,8,0,1,5,
%T A201283 9,7,1,9,9,2,9,0,4,8,0,0,4,4,9,4,6,9,7,2,4,4,2,7,5,5,8,7,8,7,1,7,9,7,
%U A201283 9,1,3,8,8,1,6,6,5,4,2,9,7,0,9,5,8,5,9,3,7,4,7,9,7,5,9,3,9,3,0
%N A201283 Decimal expansion of x satisfying x^2 + 4 = cot(x) and 0 < x < Pi.
%C A201283 See A201280 for a guide to related sequences. The Mathematica program includes a graph.
%H A201283 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A201283 0.241591857436453645370507584357801597199290...
%t A201283 a = 1; c = 4;
%t A201283 f[x_] := a*x^2 + c; g[x_] := Cot[x]
%t A201283 Plot[{f[x], g[x]}, {x, 0, Pi/2}, {AxesOrigin -> {0, 0}}]
%t A201283 r = x /. FindRoot[f[x] == g[x], {x, .2, .3}, WorkingPrecision -> 110]
%t A201283 RealDigits[r] (* A201283 *)
%Y A201283 Cf. A201280.
%K A201283 nonn,cons
%O A201283 0,1
%A A201283 _Clark Kimberling_, Nov 29 2011