login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093828 Decimal expansion of (3*Pi)/8. 4

%I

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

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

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

%N Decimal expansion of (3*Pi)/8.

%C Area of an astroid with a = 1.

%H Harry J. Smith, <a href="/A093828/b093828.txt">Table of n, a(n) for n = 1..20000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Astroid.html">Astroid</a>

%F Equals Integral_{x>0} sin(x)^3/x^3. - _Jean-Fran├žois Alcover_, Jun 04 2013

%F From _Amiram Eldar_, Aug 02 2020: (Start)

%F Equals arctan(1 + sqrt(2)).

%F Equals Integral_{x=0..1} x^(3/2)/sqrt(1-x) dx. (End)

%e 1.1780972450961724644234912687298135815739385247656646...

%p evalf[110](3*Pi*(1/8)); # _G. C. Greubel_, Aug 11 2019

%t RealDigits[3*Pi/8, 10, 105][[1]] (* _G. C. Greubel_, Aug 11 2019 *)

%o (PARI) { default(realprecision, 20080); x=3*Pi/8; for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b093828.txt", n, " ", d)); } \\ _Harry J. Smith_, Jun 18 2009

%o (MAGMA) SetDefaultRealField(RealField(110)); R:= RealField(); 3*Pi(R)/8; // _G. C. Greubel_, Aug 11 2019

%o (Sage) numerical_approx(3*pi/8, digits=110) # _G. C. Greubel_, Aug 11 2019

%Y Cf. A161685 (continued fraction). - _Harry J. Smith_, Jun 18 2009

%K nonn,cons,easy

%O 1,3

%A _Eric W. Weisstein_, Apr 16 2004

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 18 15:48 EDT 2020. Contains 337169 sequences. (Running on oeis4.)