A019938 Decimal expansion of tangent of 40 degrees.

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

Offset

0,1

Comments

Also the decimal expansion of cotangent of 50 degrees. - Ivan Panchenko, Aug 01 2014

Links

Ivan Panchenko, Table of n, a(n) for n = 0..1000

Index entries for algebraic numbers, degree 6.

Example

0.839099631177280011763127298123181364687434283012346533244102...

Mathematica

RealDigits[Tan[2*Pi/9], 10, 100][[1]] (* G. C. Greubel, Nov 25 2018 *)
RealDigits[Tan[40 Degree], 10, 120][[1]] (* Harvey P. Dale, Apr 06 2022 *)

Prog

(PARI) default(realprecision, 100); tan(2*Pi/9) \\ G. C. Greubel, Nov 25 2018
(PARI) polrootsreal(x^6-33*x^4+27*x^2-3)[5] \\ Charles R Greathouse IV, Feb 05 2025
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(2*Pi(R)/9); // G. C. Greubel, Nov 25 2018
(Sage) numerical_approx(tan(2*pi/9), digits=100) # G. C. Greubel, Nov 25 2018

Crossrefs

Cf. A019849 (sine of 40 degrees).

Sequence in context: A024568 A166202 A146482 * A170937 A058265 A357528

Adjacent sequences: A019935 A019936 A019937 * A019939 A019940 A019941

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved