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A042292 Numerators of continued fraction convergents to sqrt(672). 2
25, 26, 311, 337, 17161, 17498, 209639, 227137, 11566489, 11793626, 141296375, 153090001, 7795796425, 7948886426, 95233547111, 103182433537, 5254355223961, 5357537657498, 64187269456439 (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 (0,0,0,674,0,0,0,-1).

FORMULA

G.f.: (25 +26*x +311*x^2 +337*x^3 +311*x^4 -26*x^5 +25*x^6 -x^7)/(1 -674*x^4 +x^8). - Vincenzo Librandi, Nov 21 2013

a(n) = 674*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 21 2013

MATHEMATICA

Numerator[Convergents[Sqrt[672], 30]] (* or *) CoefficientList[Series[(25 + 26 x + 311 x^2 + 337 x^3 + 311 x^4 - 26 x^5 + 25 x^6 - x^7)/(1 - 674 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 21 2013 *)

PROG

(MAGMA) I:=[25, 26, 311, 337, 17161, 17498, 209639, 227137]; [n le 8 select I[n] else 674*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 21 2013

CROSSREFS

Cf. A042293.

Sequence in context: A042286 A042288 A042290 * A042294 A041311 A042296

Adjacent sequences:  A042289 A042290 A042291 * A042293 A042294 A042295

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 19 11:58 EDT 2021. Contains 343114 sequences. (Running on oeis4.)