A249521 Decimal expansion of 4/sqrt(Pi), the average distance between two random Gaussian points in three dimensions.

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

Offset

1,1

Comments

Coordinates are independent normally distributed random variables with mean 0 and variance 1.

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

Steven R. Finch, Random Triangles, Jan 21 2010. [Cached copy, with permission of the author]

Index entries for transcendental numbers.

Formula

Equals Sum_{k>=0} k!/(k+3/2)!. - Amiram Eldar, Jun 19 2023

Example

2.25675833419102514779231780624309034337620251731...

Mathematica

RealDigits[4/Sqrt[Pi], 10, 103] // First

Prog

(PARI) 4/sqrt(Pi) \\ G. C. Greubel, Jan 09 2017

Crossrefs

Cf. A002161 (the analog constant in two dimensions), A087197, A190732 (the analog constant in one dimension).

Sequence in context: A209527 A054255 A063177 * A355345 A034803 A205885

Adjacent sequences: A249518 A249519 A249520 * A249522 A249523 A249524

Keyword

nonn,cons,easy

Author

Jean-François Alcover, Oct 31 2014

Status

approved