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A041853 Denominators of continued fraction convergents to sqrt(448). 2
1, 6, 253, 1524, 64261, 387090, 16322041, 98319336, 4145734153, 24972724254, 1053000152821, 6342973641180, 267457893082381, 1611090332135466, 67933251842771953, 409210601388767184, 17254778510170993681, 103937881662414729270, 4382645808331589623021 (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 (0,254,0,-1).

FORMULA

G.f.: -(x^2 -6*x -1) / ((x^2 -16*x +1)*(x^2 +16*x +1)). - Colin Barker, Nov 26 2013

a(n) = 254*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 25 2013

MATHEMATICA

Denominator/@Convergents[Sqrt[448], 20] (* Harvey P. Dale, Apr 06 2011 *)

PROG

(Magma) I:=[1, 6, 253, 1524]; [n le 4 select I[n] else 254*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 25 2013

CROSSREFS

Cf. A041852, A040426.

Sequence in context: A324478 A230881 A332563 * A168476 A320979 A279869

Adjacent sequences: A041850 A041851 A041852 * A041854 A041855 A041856

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 26 2013

STATUS

approved

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Last modified January 28 12:20 EST 2023. Contains 359872 sequences. (Running on oeis4.)