OFFSET
0,1
COMMENTS
The length of the line underlying an arc of one radian with radius 1 (i.e., the linear distance for ends of an arc length 1 having same length as radius).
Also equals i*e^(-i/2) - i*e^(i/2).
FORMULA
Equals 2*A201504.
Equals Sum_{k>=0} 2*(-1)^k*(1/2 - Pi/2)^(2*k)/(2*k)!. - Ilya Gutkovskiy, May 22 2016
EXAMPLE
0.958851077208406000546575870431142776163606735881201350377...
MATHEMATICA
RealDigits[2 Sin[1/2], 10, 100][[1]] (* Ilya Gutkovskiy, May 22 2016 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Peter M. Chema, May 22 2016
EXTENSIONS
More digits from Jon E. Schoenfield, Mar 15 2018
STATUS
approved