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A040387 Continued fraction for sqrt(408). 2
20, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40, 5, 40 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..74.

Index entries for continued fractions for constants

Index entries for linear recurrences with constant coefficients, signature (0,1).

FORMULA

a(n)=(1/2)*[45+35*(-1)^n]-20*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava, Apr 30 2009]

a(n) = 5*(9+7*(-1)^n)/2 for n>0. a(n) = a(n-2) for n>2. G.f.: -5*(4*x^2+x+4) / ((x-1)*(x+1)). [Colin Barker, Mar 25 2013]

MAPLE

with(numtheory): Digits := 300: convert(evalf(sqrt(408)), confrac);

CROSSREFS

Sequence in context: A104158 A068612 A233820 * A201137 A040385 A161997

Adjacent sequences:  A040384 A040385 A040386 * A040388 A040389 A040390

KEYWORD

nonn,cofr,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified July 18 21:25 EDT 2019. Contains 325144 sequences. (Running on oeis4.)