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A042402 Numerators of continued fraction convergents to sqrt(728). 2
26, 27, 1430, 1457, 77194, 78651, 4167046, 4245697, 224943290, 229188987, 12142770614, 12371959601, 655484669866, 667856629467, 35384029402150, 36051886031617, 1910082103046234, 1946133989077851 (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, 54, 0, -1).

FORMULA

G.f.: (26 +27*x +26*x^2 -x^3)/(1 -54*x^2 +x^4). - Vincenzo Librandi, Nov 23 2013

a(n) = 54*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 23 2013

MATHEMATICA

Numerator[Convergents[Sqrt[728], 30]] (* Harvey P. Dale, Feb 24 2013 *)

CoefficientList[Series[(26 + 27 x + 26 x^2 - x^3)/(1 - 54 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 23 2013 *)

PROG

(MAGMA) I:=[26, 27, 1430, 1457]; [n le 4 select I[n] else 54*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 23 2013

CROSSREFS

Cf. A042403.

Sequence in context: A042398 A042400 A042401 * A247394 A056081 A081644

Adjacent sequences:  A042399 A042400 A042401 * A042403 A042404 A042405

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 18 17:45 EST 2019. Contains 329287 sequences. (Running on oeis4.)