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A041325 Denominators of continued fraction convergents to sqrt(176). 2
1, 3, 4, 15, 394, 1197, 1591, 5970, 156811, 476403, 633214, 2376045, 62410384, 189607197, 252017581, 945659940, 24839176021, 75463188003, 100302364024, 376370280075, 9885929645974, 30034159217997, 39920088863971, 149794425809910, 3934575159921631 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,0,0,398,0,0,0,-1).

FORMULA

G.f.: -(x^2-3*x-1)*(x^4+5*x^2+1) / ((x^4-20*x^2+1)*(x^4+20*x^2+1)). - Colin Barker, Nov 15 2013

a(n) = 398*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 15 2013

MATHEMATICA

Denominator[Convergents[Sqrt[176], 30]] (* Vincenzo Librandi, Dec 15 2013 *)

PROG

(MAGMA) I:=[1, 3, 4, 15, 394, 1197, 1591, 5970]; [n le 8 select I[n] else 398*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 15 2013

CROSSREFS

Cf. A041324, A010220.

Sequence in context: A331869 A115752 A103095 * A042541 A325212 A329890

Adjacent sequences:  A041322 A041323 A041324 * A041326 A041327 A041328

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 15 2013

STATUS

approved

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Last modified April 5 09:34 EDT 2020. Contains 333239 sequences. (Running on oeis4.)