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A041601 Denominators of continued fraction convergents to sqrt(318). 2
1, 1, 5, 6, 209, 215, 1069, 1284, 44725, 46009, 228761, 274770, 9570941, 9845711, 48953785, 58799496, 2048136649, 2106936145, 10475881229, 12582817374, 438291671945, 450874489319, 2241789629221, 2692664118540, 93792369659581, 96485033778121 (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 (0,0,0,214,0,0,0,-1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+6*x^2+1) / (x^8-214*x^4+1). - Colin Barker, Nov 19 2013

a(n) = 214*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 21 2013

MATHEMATICA

Denominator[Convergents[Sqrt[318], 30]] (* Vincenzo Librandi Dec 21 2013 *)

PROG

(MAGMA) I:=[1, 1, 5, 6, 209, 215, 1069, 1284]; [n le 8 select I[n] else 214*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 21 2013

CROSSREFS

Cf. A041600, A040300.

Sequence in context: A041257 A041411 A103089 * A301648 A041827 A042089

Adjacent sequences:  A041598 A041599 A041600 * A041602 A041603 A041604

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 19 2013

STATUS

approved

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Last modified January 19 20:41 EST 2020. Contains 331066 sequences. (Running on oeis4.)