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A042911
Denominators of continued fraction convergents to sqrt(987).
2
1, 2, 5, 12, 749, 1510, 3769, 9048, 564745, 1138538, 2841821, 6822180, 425816981, 858456142, 2142729265, 5143914672, 321065438929, 647274792530, 1615615023989, 3878504840508, 242082915135485, 488044335111478, 1218171585358441, 2924387505828360
OFFSET
0,2
LINKS
FORMULA
G.f.: -(x^2-2*x-1)*(x^4+6*x^2+1) / (x^8-754*x^4+1). - Colin Barker, Dec 25 2013
a(n) = 754*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Feb 01 2014
MATHEMATICA
Denominator[Convergents[Sqrt[987], 30]] (* Vincenzo Librandi, Feb 01 2014 *)
PROG
(Magma) I:=[1, 2, 5, 12, 749, 1510, 3769, 9048]; [n le 8 select I[n] else 754*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Feb 01 2014
CROSSREFS
Sequence in context: A197950 A041715 A042241 * A137918 A372875 A114502
KEYWORD
nonn,frac,easy
EXTENSIONS
More terms from Colin Barker, Dec 25 2013
STATUS
approved