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A041183
Denominators of continued fraction convergents to sqrt(102).
2
1, 10, 201, 2020, 40601, 408030, 8201201, 82420040, 1656602001, 16648440050, 334625403001, 3362902470060, 67592674804201, 679289650512070, 13653385685045601, 137213146500968080, 2757916315704407201, 27716376303545040090, 557085442386605209001
OFFSET
0,2
FORMULA
G.f.: (1 +10*x -x^2)/(1 -202*x^2 +x^4). - Vincenzo Librandi, Dec 12 2013
a(n) = 202*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 12 2013
MATHEMATICA
Denominator[Convergents[Sqrt[102], 40]] (* Harvey P. Dale, Sep 29 2011 *)
CoefficientList[Series[(1 + 10 x - x^2)/(1 - 202 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 12 2013 *)
PROG
(Magma) I:=[1, 10, 201, 2020]; [n le 4 select I[n] else 202*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 12 2013
CROSSREFS
Cf. A041182.
Sequence in context: A362723 A178020 A279833 * A210168 A041180 A367200
KEYWORD
nonn,frac,easy
EXTENSIONS
More terms from Vincenzo Librandi, Dec 12 2013
STATUS
approved