A019955 Decimal expansion of tangent of 57 degrees.

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

Offset

1,2

Comments

Also the decimal expansion of cotangent of 33 degrees. - Ivan Panchenko, Sep 01 2014

Links

Ivan Panchenko, Table of n, a(n) for n = 1..1000

Wikipedia, Exact trigonometric constants

Formula

Equals cot(11*Pi/90) = (1/4)*(2 - sqrt(2*(5 - sqrt(5))))*(2 - (2 + sqrt(3))*(3 + sqrt(5))). - G. C. Greubel, Nov 22 2018

Example

1.5398649638145829048267969726027801257083870321654816797991855...

Mathematica

RealDigits[Tan[57 Degree], 10, 120][[1]] (* Harvey P. Dale, Jul 20 2016 *)
RealDigits[Tan[19*Pi/60], 10, 100][[1]] (* G. C. Greubel, Nov 22 2018 *)

Prog

(PARI) default(realprecision, 100); tan(19*Pi/60) \\ G. C. Greubel, Nov 22 2018
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(19*Pi(R)/60); // G. C. Greubel, Nov 22 2018
(Sage) numerical_approx(tan(19*pi/60), digits=100) # G. C. Greubel, Nov 22 2018

Crossrefs

Cf. A019866 (sine of 56 degrees).

Sequence in context: A201938 A201410 A332528 * A296345 A317907 A075693

Adjacent sequences: A019952 A019953 A019954 * A019956 A019957 A019958

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved