Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Jun 25 2021 06:19:25
%S 4,7,3,8,7,7,2,6,2,2,4,2,3,2,5,8,2,9,7,9,7,9,2,8,1,5,8,7,4,1,4,3,9,7,
%T 9,1,1,1,7,3,4,7,0,8,9,6,4,4,3,0,9,6,8,4,3,9,2,2,4,1,1,2,7,3,0,7,7,0,
%U 9,4,2,2,0,9,8,7,0,2,7,7,4,6,1,6,8,3,7,7,3,0,2,4,4,2,3,8,3,9,0,2,7,4,0,1,3
%N Decimal expansion of the mean distance between two points picked at random in a quarter-disk.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CircularSectorLinePicking.html">Circular Sector Line Picking</a>.
%F Equals (32*(3 - 94*sqrt(2) + 48*Pi + 6*log(-2 + 2*sqrt(2))))/(135*Pi^2).
%e 0.47387726224232582979...
%t RealDigits[32*(3 - 94*Sqrt[2] + 48*Pi + 6*Log[2*(Sqrt[2]-1)])/(135*Pi^2), 10, 100][[1]] (* _Amiram Eldar_, Jun 25 2021 *)
%o (PARI) (32*(3 - 94*sqrt(2) + 48*Pi + 6*log(-2 + 2*sqrt(2))))/(135*Pi^2) \\ _Michel Marcus_, Jun 25 2021
%Y Cf. A093070, A130203.
%K nonn,cons
%O 0,1
%A _Eric W. Weisstein_, May 16 2007