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A014549 Decimal expansion of 1 / M(1,sqrt(2)) (Gauss's constant). +0
7
8, 3, 4, 6, 2, 6, 8, 4, 1, 6, 7, 4, 0, 7, 3, 1, 8, 6, 2, 8, 1, 4, 2, 9, 7, 3, 2, 7, 9, 9, 0, 4, 6, 8, 0, 8, 9, 9, 3, 9, 9, 3, 0, 1, 3, 4, 9, 0, 3, 4, 7, 0, 0, 2, 4, 4, 9, 8, 2, 7, 3, 7, 0, 1, 0, 3, 6, 8, 1, 9, 9, 2, 7, 0, 9, 5, 2, 6, 4, 1, 1, 8, 6, 9, 6, 9, 1, 1, 6, 0, 3, 5, 1, 2, 7, 5, 3, 2 (list; cons; graph; listen)
OFFSET

0,1

COMMENT

On May 30, 1799, Gauss discovered that this number is also equal to (2/Pi)*Integral(1/sqrt(1-t^4),t=0..1).

M(a,b) is the limit of the arithmetic-geometric mean iteration applied repeatedly starting with a and b: a_0=a, b_0=b, a_{n+1}=(a_n+b_n)/2, b_{n+1}=sqrt(a_n*b_n).

REFERENCES

J. M. Borwein and P. B. Borwein, Pi and the AGM, page 5.

J. R. Goldman, The Queen of Mathematics, 1998, p. 92.

LINKS

Harry J. Smith, Table of n, a(n) for n=0,...,20000

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Eric Weisstein's World of Mathematics, Arithmetic-Geometric Mean

EXAMPLE

0.8346268416740731862814297327990468...

PROGRAM

(PARI) { default(realprecision, 20080); x=10*agm(1, sqrt(2))^-1; for (n=0, 20000, d=floor(x); x=(x-d)*10; write("b014549.txt", n, " ", d)); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Apr 20 2009]

CROSSREFS

Cf. A053002, A053003, A053004.

Adjacent sequences: A014546 A014547 A014548 this_sequence A014550 A014551 A014552

Sequence in context: A070597 A091895 A111436 this_sequence A021549 A013665 A110234

KEYWORD

nonn,cons,nice

AUTHOR

Eric Weisstein (eric(AT)weisstein.com), N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Fixed my PARI program, had -n Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 19 2009

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Last modified July 4 09:27 EDT 2009. Contains 160562 sequences.


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