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A272795 Decimal expansion of 2*sin(1/2). 0
9, 5, 8, 8, 5, 1, 0, 7, 7, 2, 0, 8, 4, 0, 6, 0, 0, 0, 5, 4, 6, 5, 7, 5, 8, 7, 0, 4, 3, 1, 1, 4, 2, 7, 7, 6, 1, 6, 3, 6, 0, 6, 7, 3, 5, 8, 8, 1, 2, 0, 1, 3, 5, 0, 3, 7, 7, 2, 3, 3, 2, 2, 6, 2, 5, 1, 0, 7, 0, 0, 0, 0, 5, 7, 5, 6, 2, 9, 6, 6, 4, 4, 1, 9, 2, 6, 2 (list; constant; graph; refs; listen; history; text; internal format)
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).

LINKS

Table of n, a(n) for n=0..86.

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

Sequence in context: A309645 A146483 A090463 * A246765 A191759 A289505

Adjacent sequences:  A272792 A272793 A272794 * A272796 A272797 A272798

KEYWORD

nonn,cons

AUTHOR

Peter M. Chema, May 22 2016

EXTENSIONS

More digits from Jon E. Schoenfield, Mar 15 2018

STATUS

approved

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Last modified April 6 08:53 EDT 2020. Contains 333268 sequences. (Running on oeis4.)