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A040002 Continued fraction for sqrt(5). 5
2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

G. Xiao, Contfrac

Index entries for continued fractions for constants

Index to divisibility sequences

FORMULA

a(n)=4-2*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava, Jun 11 2009]

EXAMPLE

2.236067977499789696409173668... = 2 + 1/(4 + 1/(4 + 1/(4 + 1/(4 + ...)))) [From Harry J. Smith, Jun 01 2009]

MAPLE

Digits := 100: convert(evalf(sqrt(N)), confrac, 90, 'cvgts'):

MATHEMATICA

ContinuedFraction[Sqrt[5], 300] (*From Vladimir Joseph Stephan Orlovsky, Mar 04 2011*)

PROG

(PARI) { allocatemem(932245000); default(realprecision, 26000); x=contfrac(sqrt(5)); for (n=0, 20000, write("b040002.txt", n, " ", x[n+1])); } [From Harry J. Smith, Jun 01 2009]

CROSSREFS

Cf. A002163 Decimal expansion.

Sequence in context: A036264 A105192 A203638 * A151798 A035684 A049111

Adjacent sequences:  A039999 A040000 A040001 * A040003 A040004 A040005

KEYWORD

nonn,cofr,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 20 16:29 EDT 2014. Contains 240807 sequences.