A019961 Decimal expansion of tangent of 63 degrees.

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

Offset

1,2

Comments

Also the decimal expansion of cotangent of 27 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(3*Pi/20) = sqrt(5) - 1 + sqrt(5 - 2*sqrt(5)). - G. C. Greubel, Nov 21 2018

Example

1.96261050550515058230464042621189498505671...

Mathematica

RealDigits[Tan[7*Pi/20], 10, 100][[1]] (* G. C. Greubel, Nov 21 2018 *)

Prog

(PARI) default(realprecision, 100); tan(7*Pi/20) \\ G. C. Greubel, Nov 21 2018
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(7*Pi(R)/20); // G. C. Greubel, Nov 21 2018
(Sage) numerical_approx(tan(7*pi/20), digits=100) # G. C. Greubel, Nov 21 2018

Crossrefs

Cf. A019872 (sine of 63 degrees).

Sequence in context: A188528 A243257 A194182 * A327996 A357762 A093540

Adjacent sequences: A019958 A019959 A019960 * A019962 A019963 A019964

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved