A019857 Decimal expansion of sine of 48 degrees.

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

Offset

0,1

Comments

An algebraic number of degree 8 and denominator 2. - Charles R Greathouse IV, Aug 27 2017

Links

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

Wikipedia, Exact trigonometric constants

Index entries for algebraic numbers, degree 8

Formula

Equals cos(7*pi/30) = 2F1(17/20,3/20;1/2;3/4) / 2. - R. J. Mathar, Oct 27 2008

Equals 2*A019833*A019875. - R. J. Mathar, Jan 17 2021

Equals 1/(sqrt(5+2*sqrt(5))-sqrt(3)). - Seiichi Manyama, Mar 19 2021

4*this^3 -3*this = -A019845. - R. J. Mathar, Aug 29 2025

One of the 8 real-valued roots of 256*x^8-448*x^6+224*x^4-32*x^2+1=0. - R. J. Mathar, Aug 31 2025

Example

0.74314482...

Mathematica

RealDigits[ Sin[4 Pi/15], 10, 111] (* Robert G. Wilson v *)

Prog

(PARI) sin(4*Pi/15) \\ Charles R Greathouse IV, Aug 27 2017

Crossrefs

Cf. A019833, A019875.

Sequence in context: A200687 A200121 A198348 * A385241 A363093 A296474

Adjacent sequences: A019854 A019855 A019856 * A019858 A019859 A019860

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved