A200410 - OEIS

%I #9 Apr 08 2026 08:46:14

%S 1,4,6,7,1,0,7,0,6,7,9,4,7,8,9,4,0,0,2,3,4,3,2,4,8,3,6,3,2,3,9,3,6,5,

%T 8,0,8,2,6,6,0,9,4,3,7,9,9,7,6,0,2,3,2,3,4,2,5,2,4,8,0,9,9,2,0,7,4,3,

%U 8,3,7,5,3,0,8,5,7,7,5,7,1,5,9,5,6,5,4,2,7,7,4,9,6,7,6,5,7,5,3

%N Decimal expansion of least x>0 satisfying 4*x^2+1=tan(x).

%C See A200338 for a guide to related sequences. The Mathematica program includes a graph.

%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.

%e 1.4671070679478940023432483632393658082660943799...

%t a = 4; b = 0; c = 1;

%t f[x_] := a*x^2 + b*x + c; g[x_] := Tan[x]

%t Plot[{f[x], g[x]}, {x, -.1, Pi/2}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]

%t RealDigits[r]   (* A200410 *)

%Y Cf. A200338.

%K nonn,cons

%O 1,2

%A _Clark Kimberling_, Nov 17 2011