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A041609
Denominators of continued fraction convergents to sqrt(322).
2
1, 1, 17, 18, 629, 647, 10981, 11628, 406333, 417961, 7093709, 7511670, 262490489, 270002159, 4582525033, 4852527192, 169568449561, 174420976753, 2960304077609, 3134725054362, 109540955925917, 112675680980279, 1912351851610381, 2025027532590660
OFFSET
0,3
FORMULA
G.f.: -(x^2-x-1)*(x^4+18*x^2+1) / (x^8-646*x^4+1). - Colin Barker, Nov 19 2013
a(n) = 646*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 21 2013
MATHEMATICA
Denominator[Convergents[Sqrt[322], 30]] (* Harvey P. Dale, Apr 25 2012 *)
CoefficientList[Series[-(x^2 - x - 1) (x^4 + 18 x^2 + 1)/(x^8 - 646 x^4 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 21 2013 *)
PROG
(Magma) I:=[1, 1, 17, 18, 629, 647, 10981, 11628]; [n le 8 select I[n] else 646*Self(n-4)-Self(n-8): n in [1..70]]; // Vincenzo Librandi, Dec 21 2013
CROSSREFS
Sequence in context: A197351 A041143 A041608 * A041610 A042399 A156656
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 19 2013
STATUS
approved