A130204 Decimal expansion of the mean distance between two points picked at random in a quarter-disk.

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, 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, 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

Offset

0,1

Links

Table of n, a(n) for n=0..104.

Eric Weisstein's World of Mathematics, Circular Sector Line Picking.

George B. McClellan Zerr, Solution to Problem 11031, Mathematical questions and solutions from the "Educational Times", Vol. 55 (1891), pp. 137-138.

Formula

Equals (32*(3 - 94*sqrt(2) + 48*Pi + 6*log(-2 + 2*sqrt(2))))/(135*Pi^2).

Example

0.47387726224232582979...

Mathematica

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 *)

Prog

(PARI) (32*(3 - 94*sqrt(2) + 48*Pi + 6*log(-2 + 2*sqrt(2))))/(135*Pi^2) \\ Michel Marcus, Jun 25 2021

Crossrefs

Cf. A093070, A130203.

Sequence in context: A296499 A199446 A100127 * A021215 A063378 A384161

Adjacent sequences: A130201 A130202 A130203 * A130205 A130206 A130207

Keyword

nonn,cons

Author

Eric W. Weisstein, May 16 2007

Status

approved