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A042456 Numerators of continued fraction convergents to sqrt(756). 2
27, 55, 2997, 6049, 329643, 665335, 36257733, 73180801, 3988020987, 8049222775, 438646050837, 885341324449, 48247077571083, 97379496466615, 5306739886768293, 10710859270003201, 583693140466941147 (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 (0,110,0,-1).

FORMULA

G.f.: (27 +55*x +27*x^2 -x^3)/(1 -110*x^2 +x^4). - Vincenzo Librandi, Nov 25 2013

a(n) = 110*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 25 2013

MATHEMATICA

Numerator[Convergents[Sqrt[756], 30]] (* Harvey P. Dale, Sep 14 2012 *)

CoefficientList[Series[(27 + 55 x + 27 x^2 - x^3)/(1 - 110 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)

PROG

(MAGMA) I:=[27, 55, 2997, 6049]; [n le 4 select I[n] else 110*Self(n-2)-Self(n-4): n in [1..30]]; //  Vincenzo Librandi, Nov 25 2013

CROSSREFS

Cf. A042457.

Sequence in context: A042450 A042452 A042454 * A132768 A053180 A080864

Adjacent sequences:  A042453 A042454 A042455 * A042457 A042458 A042459

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified July 18 21:25 EDT 2019. Contains 325144 sequences. (Running on oeis4.)