A019978 Decimal expansion of tangent of 80 degrees.

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

Offset

1,1

Links

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

Index entries for algebraic numbers, degree 6

Formula

Largest positive of the 6 real-valued roots of x^6-33*x^4+27*x^2-3=0. - R. J. Mathar, Aug 31 2025

Equals A019889/A019819. - R. J. Mathar, Aug 31 2025

Example

tan(4*Pi/9) = 5.67128183...

Mathematica

RealDigits[Tan[80 Degree], 10, 120][[1]] (* Harvey P. Dale, Jan 04 2013 *)

Crossrefs

Sequence in context: A081820 A306324 A214681 * A030178 A038458 A387697

Adjacent sequences: A019975 A019976 A019977 * A019979 A019980 A019981

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved