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A042681
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Denominators of continued fraction convergents to sqrt(870).
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2
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1, 2, 117, 236, 13805, 27846, 1628873, 3285592, 192193209, 387672010, 22677169789, 45742011588, 2675713841893, 5397169695374, 315711556173585, 636820282042544, 37251287914641137, 75139396111324818, 4395336262371480581, 8865811920854285980
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: -(x^2-2*x-1) / (x^4-118*x^2+1). - Colin Barker, Dec 21 2013
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MATHEMATICA
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LinearRecurrence[{0, 118, 0, -1}, {1, 2, 117, 236}, 20] (* Harvey P. Dale, Jul 16 2018 *)
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PROG
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(Magma) I:=[1, 2, 117, 236]; [n le 4 select I[n] else 118*Self(n-2)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 21 2013
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CROSSREFS
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KEYWORD
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nonn,frac,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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