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A041367
Denominators of continued fraction convergents to sqrt(198).
2
1, 14, 393, 5516, 154841, 2173290, 61006961, 856270744, 24036587793, 337368499846, 9470354583481, 132922332668580, 3731295669303721, 52371061702920674, 1470121023351082593, 20634065388618076976, 579223951904657237921, 8129769392053819407870
OFFSET
0,2
FORMULA
G.f.: -(x^2-14*x-1) / (x^4-394*x^2+1). - Colin Barker, Nov 16 2013
a(n) = 394*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 16 2013
MATHEMATICA
Denominator[Convergents[Sqrt[198], 30]] (* Harvey P. Dale, May 14 2013 *)
CoefficientList[Series[(1 + 14 x - x^2)/(x^4 - 394 x^2 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 16 2013 *)
PROG
(Magma) I:=[1, 14, 393, 5516]; [n le 4 select I[n] else 394*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 16 2013
CROSSREFS
Sequence in context: A097310 A223003 A228185 * A041364 A353609 A222904
KEYWORD
nonn,cofr,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 16 2013
STATUS
approved