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A042784 Numerators of continued fraction convergents to sqrt(923). 2
30, 61, 91, 152, 243, 638, 38523, 77684, 116207, 193891, 310098, 814087, 49155318, 99124723, 148280041, 247404764, 395684805, 1038774374, 62722147245, 126483068864, 189205216109, 315688284973, 504893501082, 1325475287137, 80033410729302 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 1276, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: (30 +61*x +91*x^2 +152*x^3 +243*x^4 +638*x^5 +243*x^6 -152*x^7 +91*x^8 -61*x^9 +30*x^10 -x^11)/(1 -1276*x^6 +x^12). - Vincenzo Librandi, Dec 04 2013

a(n) = 1276*a(n-6) - a(n-12). - Vincenzo Librandi, Dec 04 2013

MATHEMATICA

Numerator[Convergents[Sqrt[923], 30]] (* or *) CoefficientList[Series[(30 + 61 x + 91 x^2 + 152 x^3 + 243 x^4 + 638 x^5 + 243 x^6 - 152 x^7 + 91 x^8 - 61 x^9 + 30 x^10 - x^11)/(1 - 1276 x^6 + x^12), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 04 2013 *)

PROG

(MAGMA) I:=[30, 61, 91, 152, 243, 638, 38523, 77684, 116207, 193891, 310098, 814087]; [n le 12 select I[n] else 1276*Self(n-6)-Self(n-12): n in [1..30]]; // Vincenzo Librandi, Dec 04 2013

CROSSREFS

Cf. A042785.

Sequence in context: A228877 A258879 A053014 * A042786 A042782 A042780

Adjacent sequences:  A042781 A042782 A042783 * A042785 A042786 A042787

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Vincenzo Librandi, Dec 04 2013

STATUS

approved

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Last modified October 15 03:04 EDT 2019. Contains 328025 sequences. (Running on oeis4.)