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A041753 Denominators of continued fraction convergents to sqrt(396). 2
1, 1, 9, 10, 389, 399, 3581, 3980, 154821, 158801, 1425229, 1584030, 61618369, 63202399, 567237561, 630439960, 24523956041, 25154396001, 225759124049, 250913520050, 9760472885949, 10011386405999, 89851564133941, 99862950539940, 3884643684651661 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
G.f.: -(x^2-x-1)*(x^4+10*x^2+1) / ((x^4-20*x^2+1)*(x^4+20*x^2+1)). - Colin Barker, Nov 23 2013
a(n) = 398*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 24 2013
MATHEMATICA
Denominator[Convergents[Sqrt[396], 30]] (* Vincenzo Librandi, Dec 24 2013 *)
PROG
(Magma) I:=[1, 1, 9, 10, 389, 399, 3581, 3980]; [n le 8 select I[n] else 398*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 24 2013
CROSSREFS
Sequence in context: A119159 A041415 A103869 * A042191 A042729 A156292
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 23 2013
STATUS
approved

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)