A396274 - OEIS

%I #6 May 21 2026 07:55:02

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

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

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

%N Decimal expansion of the probability that the line segment connecting two points, chosen independently and uniformly at random in an annulus with a radii ratio of 1:2, lies entirely within the annulus.

%H Jonathan K. Hodge, Emily Marshall, and Geoff Patterson, <a href="https://www.jstor.org/stable/10.4169/074683410x510317">Gerrymandering and Convexity</a>, The College Mathematics Journal, Vol. 41, No. 4 (2010), pp. 312-324.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConvexityCoefficient.html">Convexity Coefficient</a>.

%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.

%F Equals 8/9 - 2/(sqrt(3)*Pi).

%F Equals 8/9 - A165952.

%e 0.521336291941027522548004556680242594623964568644461...

%t RealDigits[8/9 - 2/(Sqrt[3]*Pi), 10, 120][[1]]

%o (PARI) 8/9 - 2/(sqrt(3)*Pi)

%Y Cf. A165952, A395391, A396275.

%K nonn,cons

%O 0,1

%A _Amiram Eldar_, May 21 2026