

A153799


Decimal expansion of 4  Pi.


4



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

0,1


COMMENTS

Given a square with a side measuring 2 units, having a circle with a radius of 2 units centered on one of its corners, and another circle also with a radius of 2 units centered on the most distant corner from the one on which the first circle is centered, there are two "zones" within the square that overlap with the area of only one of the circles. This number gives the area of either zone.  Alonso del Arte, Aug 01 2012
Area between a circle of radius 1 and the circumscribed square.  Omar E. Pol, Aug 02 2012
Perimeter of the unit square minus the circumference of its incircle.  Jonathan Sondow, Nov 23 2017


LINKS

G. C. Greubel, Table of n, a(n) for n = 0..2000


FORMULA

4  Pi = (1)(Pi  4) = (1)*Sum_{n >= 1} (4*(1)^n/(2n + 1)) = (1)*arcsin(sin 4).  Alonso del Arte, Aug 01 2012


EXAMPLE

0.8584073464102067615373566167204971158...


MATHEMATICA

RealDigits[4  Pi, 10, 100][[1]] (* Alonso del Arte, Aug 01 2012 *)


PROG

(PARI) 4Pi


CROSSREFS

Essentially the same as A030644.
Cf. A000796, A063448.
Sequence in context: A227514 A305036 A119812 * A086235 A157742 A200134
Adjacent sequences: A153796 A153797 A153798 * A153800 A153801 A153802


KEYWORD

easy,nonn,cons


AUTHOR

Omar E. Pol, Jan 25 2009


STATUS

approved



