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A041187

Denominators of continued fraction convergents to sqrt(104).

1, 5, 101, 510, 10301, 52015, 1050601, 5305020, 107151001, 541060025, 10928351501, 55182817530, 1114584702101, 5628106328035, 113676711262801, 574011662642040, 11593909964103601, 58543561483160045, 1182465139627304501, 5970869259619682550

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OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,102,0,-1).

FORMULA

G.f.: (1 + 5*x - x^2)/(1 - 102*x^2 + x^4). - Vincenzo Librandi, Dec 12 2013

a(n) = 102*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 12 2013

MATHEMATICA

Denominator[Convergents[Sqrt[104], 30]] (* or *) CoefficientList[Series[(1 + 5 x - x^2)/(1 - 102 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 12 2013 *)

LinearRecurrence[{0, 102, 0, -1}, {1, 5, 101, 510}, 30] (* Harvey P. Dale, Mar 12 2015 *)

PROG

(Magma) I:=[1, 5, 101, 510]; [n le 4 select I[n] else 102*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 12 2013

CROSSREFS

Cf. A041186.

Sequence in context: A087456 A081220 A210362 * A266235 A266452 A354332

Adjacent sequences: A041184 A041185 A041186 * A041188 A041189 A041190

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Vincenzo Librandi, Dec 12 2013

STATUS

approved

URL: https://oeis.org/A041187

⇱ A041187 - OEIS