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A087197 Decimal expansion of 1/sqrt(Pi). 20
5, 6, 4, 1, 8, 9, 5, 8, 3, 5, 4, 7, 7, 5, 6, 2, 8, 6, 9, 4, 8, 0, 7, 9, 4, 5, 1, 5, 6, 0, 7, 7, 2, 5, 8, 5, 8, 4, 4, 0, 5, 0, 6, 2, 9, 3, 2, 8, 9, 9, 8, 8, 5, 6, 8, 4, 4, 0, 8, 5, 7, 2, 1, 7, 1, 0, 6, 4, 2, 4, 6, 8, 4, 4, 1, 4, 9, 3, 4, 1, 4, 4, 8, 6, 7, 4, 3, 6, 6, 0, 2, 0, 2, 1, 0, 7, 3, 6, 3, 4, 4, 3, 0, 2, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Radius of a circle with area 1.

Expectation of the maximum of a size 2 sample from a normal (0,1) distribution. - Jean-François Alcover, Jun 05 2014

REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.16 Extreme value constants, p. 365.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..5000

Eric Weisstein's World of Mathematics, Inverse Erf

Index entries for transcendental numbers

FORMULA

Equals lim_{n -> infinity} Catalan(n)/(4^n*n^(-3/2)). - Jean-François Alcover, May 23 2013

Equals Sum_{k>=1} k/(2^k * Gamma(k+3/2)). - Amiram Eldar, May 27 2021

EXAMPLE

0.56418958354775628694...

MATHEMATICA

RealDigits[1/Sqrt[Pi], 10, 50][[1]] (* G. C. Greubel, Jan 09 2017 *)

PROG

(PARI) Pi^-.5 \\ Charles R Greathouse IV, Nov 13 2015

CROSSREFS

Cf. A086201, A087198, A087199.

Sequence in context: A257837 A099038 A064206 * A221216 A229073 A019818

Adjacent sequences:  A087194 A087195 A087196 * A087198 A087199 A087200

KEYWORD

cons,easy,nonn

AUTHOR

Sven Simon, Aug 24 2003

STATUS

approved

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Last modified January 27 03:09 EST 2022. Contains 350601 sequences. (Running on oeis4.)