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A042853 Denominators of continued fraction convergents to sqrt(957). 2
1, 1, 15, 31, 449, 480, 29249, 29729, 445455, 920639, 13334401, 14255040, 868636801, 882891841, 13229122575, 27341136991, 396005040449, 423346177440, 25796775686849, 26220121864289, 392878481786895, 811977085438079, 11760557677920001, 12572534763358080 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,29698,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^10 -x^9 +15*x^8 -31*x^7 +449*x^6 -480*x^5 -449*x^4 -31*x^3 -15*x^2 -x -1) / ((x^4 -31*x^2 +1)*(x^8 +31*x^6 +960*x^4 +31*x^2 +1)). - Colin Barker, Dec 25 2013

a(n) = 29698*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 25 2013

MATHEMATICA

Denominator[Convergents[Sqrt[957], 30]] (* Vincenzo Librandi, Dec 25 2013 *)

PROG

(MAGMA) I:=[1, 1, 15, 31, 449, 480, 29249, 29729, 445455, 920639, 13334401, 14255040]; [n le 12 select I[n] else 29698*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 25 2013

CROSSREFS

Cf. A042852, A040926.

Sequence in context: A102955 A041444 A041446 * A065575 A041448 A157767

Adjacent sequences:  A042850 A042851 A042852 * A042854 A042855 A042856

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 25 2013

STATUS

approved

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Last modified February 20 23:24 EST 2019. Contains 320362 sequences. (Running on oeis4.)