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A042197 Denominators of continued fraction convergents to sqrt(623). 2
1, 1, 24, 25, 1224, 1249, 29951, 31200, 1527551, 1558751, 37378824, 38937575, 1906382424, 1945319999, 46648742401, 48594062400, 2379163737601, 2427757800001, 58217593137624, 60645350937625, 2969194438143624, 3029839789081249, 72655509587012351 (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 (0,0,0,1248,0,0,0,-1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+25*x^2+1) / (x^8-1248*x^4+1). - Colin Barker, Dec 04 2013

a(n) = 1248*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Jan 16 2014

MATHEMATICA

Denominator[Convergents[Sqrt[623], 30]] (* Harvey P. Dale, Jun 28 2012 *)

PROG

(MAGMA) I:=[1, 1, 24, 25, 1224, 1249, 29951, 31200]; [n le 8 select I[n] else 1248*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Jan 16 2014

CROSSREFS

Cf. A042196, A040598.

Sequence in context: A042192 A042194 A042196 * A042198 A002924 A241042

Adjacent sequences:  A042194 A042195 A042196 * A042198 A042199 A042200

KEYWORD

nonn,cofr,frac,easy,less

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 04 2013

STATUS

approved

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Last modified March 28 07:59 EDT 2020. Contains 333079 sequences. (Running on oeis4.)