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A042202 Numerators of continued fraction convergents to sqrt(627). 2
25, 626, 31325, 783751, 39218875, 981255626, 49102000175, 1228531260001, 61475665000225, 1538120156265626, 76967483478281525, 1925725207113303751, 96363227839143469075, 2411006421185700030626, 120646684287124145000375 (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 (0,1252,0,-1).

FORMULA

G.f.: (25 +626*x +25*x^2 -x^3)/(1 -1252*x^2 +x^4). - Vincenzo Librandi, Nov 19 2013

a/n) = 1252*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 19 2013

MATHEMATICA

Numerator[Convergents[Sqrt[627], 20]] (* Harvey P. Dale, Oct 20 2012 *)

CoefficientList[Series[(25 + 626 x + 25 x^2 - x^3)/(x^4 - 1252 x^2 + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Nov 19 2013 *)

PROG

(MAGMA) I:=[25, 626, 31325, 783751]; [n le 4 select I[n] else 1252*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 19 2013

CROSSREFS

Cf. A042203.

Sequence in context: A207216 A171299 A009969 * A203341 A260048 A152256

Adjacent sequences:  A042199 A042200 A042201 * A042203 A042204 A042205

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 17 08:39 EST 2019. Contains 329217 sequences. (Running on oeis4.)