OFFSET
0,1
COMMENTS
LINKS
Stanislav Sykora, Table of n, a(n) for n = 0..2000
Wikipedia, Constructible number
Wikipedia, Regular polygon
FORMULA
Equals 2*sin(Pi/9) = 2*cos(Pi*7/18) = 2*A019829.
Equals Im((4+4*sqrt(3)*i)^(1/3)). - Gerry Martens, Mar 19 2024
EXAMPLE
0.6840402866513374660881992293645191615261667350283212569300969953...
MATHEMATICA
RealDigits[N[2Sin[Pi/9], 100]][[1]] (* Robert Price, May 01 2016 *)
PROG
(PARI) 2*sin(Pi/9)
CROSSREFS
KEYWORD
AUTHOR
Stanislav Sykora, May 01 2016
STATUS
approved