login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A053003 Continued fraction for M(1,sqrt(2)). 3
1, 5, 21, 3, 4, 14, 1, 1, 1, 1, 1, 3, 1, 15, 1, 3, 8, 36, 1, 2, 5, 2, 1, 1, 2, 2, 6, 9, 1, 1, 1, 3, 1, 2, 6, 1, 5, 1, 1, 2, 1, 13, 2, 2, 5, 1, 2, 2, 1, 5, 1, 3, 1, 3, 1, 2, 2, 2, 2, 8, 3, 1, 2, 2, 1, 10, 2, 2, 2, 3, 3, 1, 7, 1, 8, 3, 1, 1, 1, 1, 1, 1, 1, 1, 5, 2, 1, 2, 17, 1, 4, 31, 2, 2, 5, 30, 1, 8, 2, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

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=1,...,20000

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

G. Xiao, Contfrac

Index entries for continued fractions for constants

EXAMPLE

1.19814023473559220743992249228...

PROG

(PARI) { allocatemem(932245000); default(realprecision, 21000); x=contfrac(agm(1, sqrt(2))); for (n=1, 20000, write("b053003.txt", n, " ", x[n])); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Apr 20 2009]

CROSSREFS

Cf. A014549, A053002, A053004.

Sequence in context: A156148 A156824 A053002 * A167202 A204914 A165204

Adjacent sequences:  A053000 A053001 A053002 * A053004 A053005 A053006

KEYWORD

nonn,cofr,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Feb 21 2000

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Feb 22 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 21:56 EST 2012. Contains 205860 sequences.