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A042920 Numerators of continued fraction convergents to sqrt(992). 2
31, 63, 3937, 7937, 496031, 999999, 62495969, 125991937, 7873996063, 15873984063, 992061007969, 1999996000001, 124991813008031, 251983622016063, 15747976378003937, 31747936378023937, 1984120031815488031, 3999988000008999999, 249983376032373487969 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0, 126, 0, -1).

FORMULA

G.f.: (31 +63*x +31*x^2 -x^3)/(1 -126*x^2 +x^4). - Vincenzo Librandi, Dec 09 2013

a(n) = 126*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 09 2013

MATHEMATICA

Numerator[Convergents[Sqrt[992], 30]] (* or *) CoefficientList[Series[(31 + 63 x + 31 x^2 - x^3)/(1 - 126 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 09 2013 *)

PROG

(MAGMA) I:=[31, 63, 3937, 7937]; [n le 4 select I[n] else 126*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 09 2013

CROSSREFS

Cf. A042921.

Sequence in context: A042914 A042916 A042918 * A247438 A132772 A116324

Adjacent sequences:  A042917 A042918 A042919 * A042921 A042922 A042923

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vincenzo Librandi, Dec 09 2013

STATUS

approved

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Last modified September 27 18:56 EDT 2021. Contains 347694 sequences. (Running on oeis4.)