OFFSET
1,1
FORMULA
7 - 56*sin(Pi/23)^2 + 112*sin(Pi/23)^4 - 64*sin(Pi/23)^6. - Charles R Greathouse IV, Mar 25 2014
EXAMPLE
5.9997796702258838608759535245920603550032897005178106973561...
MATHEMATICA
RealDigits[Total[Re[Exp[(2 Pi I)/23]^Range[-3, 3]]], 10, 120][[1]] (* Harvey P. Dale, Jan 02 2022 *)
PROG
(PARI) subst(Pol([-64, 112, -56, 7]), 'x, sin(Pi/23)^2) \\ Charles R Greathouse IV, Mar 25 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
N. J. A. Sloane, May 03 2009, based on a posting to the Number Theory List by Nigel Boston, Apr 29 2009
STATUS
approved