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A042406 Numerators of continued fraction convergents to sqrt(731). 2
27, 730, 39447, 1065799, 57592593, 1556065810, 84085146333, 2271855016801, 122764256053587, 3316906768463650, 179235729753090687, 4842681610101912199, 261684042675256349433, 7070311833842023346890, 382058523070144517081493 (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 (0,1460,0,-1).

FORMULA

G.f.: (27 +730*x +27*x^2 -x^3)/(1 -1460*x^2 +x^4). - Vincenzo Librandi, Nov 23 2013

a(n) = 1460*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 23 2013

MATHEMATICA

Numerator[Convergents[Sqrt[731], 30]] (* or *) CoefficientList[Series[(27 + 730 x + 27 x^2 - x^3)/(1 - 1460 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 23 2013 *)

PROG

(MAGMA) I:=[27, 730, 39447, 1065799]; [n le 4 select I[n] else 1460*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 23 2013

CROSSREFS

Cf. A042407.

Sequence in context: A268015 A009971 A046240 * A279652 A284039 A159668

Adjacent sequences:  A042403 A042404 A042405 * A042407 A042408 A042409

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified March 18 12:10 EDT 2019. Contains 321283 sequences. (Running on oeis4.)