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A041439 Denominators of continued fraction convergents to sqrt(235). 2
1, 3, 91, 276, 8371, 25389, 770041, 2335512, 70835401, 214841715, 6516086851, 19763102268, 599409154891, 1817990566941, 55139126163121, 167235369056304, 5072200197852241, 15383835962613027, 466587279076243051, 1415145673191342180, 42920957474816508451 (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, 92, 0, -1).

FORMULA

G.f.: -(x^2-3*x-1) / (x^4-92*x^2+1). - Colin Barker, Nov 17 2013

a(n) = 92*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 17 2013

MATHEMATICA

Denominator[Convergents[Sqrt[235], 30]] (* Vincenzo Librandi, Dec 17 2013 *)

LinearRecurrence[{0, 92, 0, -1}, {1, 3, 91, 276}, 30] (* Harvey P. Dale, May 05 2018 *)

PROG

(MAGMA) I:=[1, 3, 91, 276]; [n le 4 select I[n] else 92*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 17 2013

CROSSREFS

Cf. A041438, A176524, A040219.

Sequence in context: A115704 A066751 A115886 * A300419 A156754 A213978

Adjacent sequences:  A041436 A041437 A041438 * A041440 A041441 A041442

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 17 2013

STATUS

approved

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Last modified February 19 20:17 EST 2019. Contains 320328 sequences. (Running on oeis4.)