OFFSET
0,2
COMMENTS
Also the imaginary part of i^(1/10). - Stanislav Sykora, Apr 25 2012
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
FORMULA
sqrt(8-2*sqrt(10+2*sqrt(5)))/4 = sqrt((1/2)*(1 - sqrt((1/8)*(5 + sqrt(5))))). - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 13 2006
EXAMPLE
0.1564344650402308690101053194671668923138...
MATHEMATICA
RealDigits[Sin[9 Degree], 10, 120][[1]] (* Harvey P. Dale, Sep 15 2014 *)
PROG
(PARI) sin(Pi/20) \\ Charles R Greathouse IV, Aug 27 2017
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
STATUS
approved