A272795 - OEIS

%I #31 Jan 04 2024 12:41:37

%S 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,

%T 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,

%U 0,0,0,0,5,7,5,6,2,9,6,6,4,4,1,9,2,6,2

%N Decimal expansion of 2*sin(1/2).

%C 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).

%C Also equals i*e^(-i/2) - i*e^(i/2).

%F Equals 2*A201504.

%F Equals Sum_{k>=0} 2*(-1)^k*(1/2 - Pi/2)^(2*k)/(2*k)!. - _Ilya Gutkovskiy_, May 22 2016

%e 0.958851077208406000546575870431142776163606735881201350377...

%t RealDigits[2 Sin[1/2], 10, 100][[1]] (* _Ilya Gutkovskiy_, May 22 2016 *)

%K nonn,cons

%O 0,1

%A _Peter M. Chema_, May 22 2016

%E More digits from _Jon E. Schoenfield_, Mar 15 2018