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A042746
Numerators of continued fraction convergents to sqrt(904).
2
30, 451, 27090, 406801, 24435150, 366934051, 22040478210, 330974107201, 19880486910270, 298538277761251, 17932177152585330, 269281195566541201, 16174803911145057390, 242891339862742402051, 14589655195675689180450, 219087719274998080108801
OFFSET
0,1
FORMULA
G.f.: -(x^3-30*x^2-451*x-30) / ((x^2-30*x-1)*(x^2+30*x-1)). - Colin Barker, Nov 09 2013
a(n) = 902*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 03 2013
MATHEMATICA
Numerator[Convergents[Sqrt[904], 30]] (* Vincenzo Librandi, Sep 25 2013 *)
CoefficientList[Series[(30 + 451 x + 30 x^2 - x^3)/(1 - 902 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 03 2013 *)
LinearRecurrence[{0, 902, 0, -1}, {30, 451, 27090, 406801}, 20] (* Harvey P. Dale, Sep 04 2023 *)
PROG
(Magma) I:=[30, 451, 27090, 406801]; [n le 4 select I[n] else 902*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 03 2013
CROSSREFS
Cf. A042747.
Sequence in context: A006421 A035710 A341559 * A281700 A024524 A081736
KEYWORD
nonn,cofr,frac,easy
AUTHOR
EXTENSIONS
Additional term from Colin Barker, Nov 09 2013
STATUS
approved