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A042575 Denominators of continued fraction convergents to sqrt(816). 2
1, 1, 2, 7, 23, 76, 99, 175, 9899, 10074, 19973, 69993, 229952, 759849, 989801, 1749650, 98970201, 100719851, 199690052, 699790007, 2299060073, 7596970226, 9896030299, 17493000525, 989504059699, 1006997060224, 1996501119923, 6996500419993, 22986002379902 (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 (0,0,0,0,0,0,0,9998,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^14 -x^13 +2*x^12 -7*x^11 +23*x^10 -76*x^9 +99*x^8 -175*x^7 -99*x^6 -76*x^5 -23*x^4 -7*x^3 -2*x^2 -x -1) / ((x^8 -100*x^4 +1)*(x^8 +100*x^4 +1)). - Colin Barker, Dec 18 2013

a(n) = 9998*a(n-8) - a(n-16) for n>15. - Vincenzo Librandi, Jan 25 2014

MATHEMATICA

Denominator/@Convergents[Sqrt[816], 30] (* Harvey P. Dale, Jun 14 2011 *)

PROG

(MAGMA) I:=[1, 1, 2, 7, 23, 76, 99, 175, 9899, 10074, 19973, 69993, 229952, 759849, 989801, 1749650]; [n le 16 select I[n] else 9998*Self(n-8)-Self(n-16): n in [1..40]]; // Vincenzo Librandi, Jan 25 2014

CROSSREFS

Cf. A042574, A040787.

Sequence in context: A030282 A291015 A273345 * A256030 A052924 A067324

Adjacent sequences:  A042572 A042573 A042574 * A042576 A042577 A042578

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 18 2013

STATUS

approved

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Last modified November 19 11:09 EST 2019. Contains 329319 sequences. (Running on oeis4.)