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A041323 Denominators of continued fraction convergents to sqrt(175). 2
1, 4, 9, 13, 35, 153, 4013, 16205, 36423, 52628, 141679, 619344, 16244623, 65597836, 147440295, 213038131, 573516557, 2507104359, 65758229891, 265540023923, 596838277737, 862378301660, 2321594881057, 10148757825888, 266189298354145, 1074905951242468 (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 (0,0,0,0,0,4048,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^10 -4*x^9 +9*x^8 -13*x^7 +35*x^6 -153*x^5 -35*x^4 -13*x^3 -9*x^2 -4*x -1) / ((x^4 -16*x^2 +1)*(x^8 +16*x^6 +255*x^4 +16*x^2 +1)). - Colin Barker, Nov 15 2013

a(n) = 4048*a(n-6) - a(n-12). - Vincenzo Librandi, Dec 15 2013

MATHEMATICA

Denominator[Convergents[Sqrt[175], 30]] (* Vincenzo Librandi, Dec 15 2013 *)

PROG

(MAGMA) I:=[1, 4, 9, 13, 35, 153, 4013, 16205, 36423, 52628, 141679, 619344]; [n le 12 select I[n] else 4048*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 15 2013

CROSSREFS

Cf. A041322, A010219.

Sequence in context: A048261 A063606 A033287 * A319217 A041028 A041211

Adjacent sequences:  A041320 A041321 A041322 * A041324 A041325 A041326

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 May 31 06:22 EDT 2020. Contains 334747 sequences. (Running on oeis4.)