A019889 Decimal expansion of sine of 80 degrees.

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

Offset

0,1

Comments

Also the real part of I^(1/9). - Stanislav Sykora, Nov 29 2013

Equals sin(4*Pi/9). - Wesley Ivan Hurt, Sep 01 2014

Links

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

Index entries for algebraic numbers, degree 6

Formula

Equals 2F1(7/12,5/12;1/2;3/4) / 2. - R. J. Mathar, Oct 27 2008

Equals 2*A019849*A019859. - R. J. Mathar, Jan 17 2021

Example

0.9848077530122080593667430245895230136706432517198424187900...

Maple

Digits:=100: evalf(sin(4*Pi/9)); # Wesley Ivan Hurt, Sep 01 2014

Mathematica

RealDigits[ Cos[Pi/18], 10, 111] (* Robert G. Wilson v *)
RealDigits[Sin[80 Degree], 10, 120][[1]] (* Harvey P. Dale, Apr 16 2022 *)

Prog

(PARI) real(I^(1/9)) \\ Michel Marcus, Nov 29 2013

Crossrefs

Sequence in context: A199862 A019720 A200117 * A243266 A358659 A010548

Adjacent sequences: A019886 A019887 A019888 * A019890 A019891 A019892

Keyword

nonn,cons

Author

N. J. A. Sloane.

Status

approved