%I #13 May 17 2023 08:41:26

%S 3,6,9,0,5,4,0,2,9,7,2,8,8,0,5,6,8,3,8,1,9,3,6,0,7,7,5,9,1,7,7,9,7,6,

%T 0,5,3,5,6,0,0,7,2,5,3,2,4,3,1,9,0,3,3,2,5,4,5,1,0,1,7,9,4,6,6,6,9,5,

%U 3,5,8,8,7,6,7,5,1,9,9,3,0,1,3,1,0,6,1,8,9,5,7,2,7,7,3,8,7,5,6,9,3,6,1,1,1

%N Decimal expansion of the open-tube surface index constant.

%C The external surface index of an open-ended cylinder (tube) equals this constant, multiplied by (Length/Diameter)^(1/3).

%C For a general definition of surface index, see A232808.

%H Stanislav Sykora, <a href="/A232817/b232817.txt">Table of n, a(n) for n = 1..1000</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Cylinder_%28geometry%29">Cylinder (geometry)</a>.

%F Equals (16*Pi)^(1/3) = 2*(2*Pi)^(1/3).

%t RealDigits[2 * Surd[2 * Pi, 3], 10, 120][[1]] (* _Amiram Eldar_, May 17 2023 *)

%Y Cf. Other surface indices: A232808 (spheres), A232809, A232810, A232811, A232812 (platonic solids), A232813 (closed cylinders), A232814 (open cylinders), A232815 (closed cones), A232816 (open cones).

%K nonn,cons,easy

%O 1,1

%A _Stanislav Sykora_, Dec 05 2013