A201940 Decimal expansion of x>0 satisfying x^2-1=e^(-x).

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

Offset: 1

Author

Clark Kimberling, Dec 13 2011

Keywords

• nonn
• cons

Comments

See A201936 for a guide to related sequences. The Mathematica program includes a graph.

Examples

			x=1.147757632144743493034371990610674766434...
		

Crossrefs

Cf. A201936.

Programs

Mathematica

a = 1; b = 0; c = -1;
f[x_] := a*x^2 + b*x + c; g[x_] := E^-x
Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, 1.1, 1.2}, WorkingPrecision -> 110]
RealDigits[r]  (* A201940 *)