OFFSET
0,1
COMMENTS
LINKS
Stanislav Sykora, Table of n, a(n) for n = 0..2000
Mauro Fiorentini, Construibili (numeri)
Eric Weisstein's World of Mathematics, Constructible Number
Wikipedia, Constructible number
Wikipedia, Regular polygon
FORMULA
Equals 2*sin(Pi/m) for m=16. Equals also sqrt(2-sqrt(2+sqrt(2))).
EXAMPLE
0.390180644032256535696569736954044481855383235503909615509004...
MATHEMATICA
RealDigits[N[2Sin[Pi/16], 100]][[1]] (* Robert Price, May 02 2016*)
PROG
(PARI) 2*sin(Pi/16)
CROSSREFS
KEYWORD
AUTHOR
Stanislav Sykora, May 02 2016
STATUS
approved