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A042872 Numerators of continued fraction convergents to sqrt(968). 2
31, 249, 280, 1929, 2209, 19601, 1217471, 9759369, 10976840, 75620409, 86597249, 768398401, 47727298111, 382586783289, 430314081400, 2964471271689, 3394785353089, 30122754096401, 1871005539329951, 14998167068736009, 16869172608065960, 116213202717131769 (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, 39202, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: (31 +249*x +280*x^2 +1929*x^3 +2209*x^4 +19601*x^5 +2209*x^6 -1929*x^7 +280*x^8 -249*x^9 +31*x^10 -x^11)/(1 -39202*x^6 +x^12). - Vincenzo Librandi, Dec 08 2013

a(n) = 39202*a(n-6) - a(n-12). - Vincenzo Librandi, Dec 08 2013

MATHEMATICA

Numerator[Convergents[Sqrt[968], 30]] (* or *) CoefficientList[Series[(31 + 249 x + 280 x^2 + 1929 x^3 + 2209 x^4 + 19601 x^5 + 2209 x^6 - 1929 x^7 + 280 x^8 -249 x^9 + 31 x^10 - x^11)/(1 - 39202 x^6 + x^12), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 08 2013 *)

LinearRecurrence[{0, 0, 0, 0, 0, 39202, 0, 0, 0, 0, 0, -1}, {31, 249, 280, 1929, 2209, 19601, 1217471, 9759369, 10976840, 75620409, 86597249, 768398401}, 30] (* Harvey P. Dale, Oct 17 2018 *)

PROG

(MAGMA) I:=[ 31, 249, 280, 1929, 2209, 19601, 1217471, 9759369, 10976840, 75620409, 86597249, 768398401]; [n le 12 select I[n] else 39202*Self(n-6)-Self(n-12): n in [1..30]]; // Vincenzo Librandi, Dec 08 2013

CROSSREFS

Cf. A042873.

Sequence in context: A321544 A147963 A027846 * A142623 A089705 A180471

Adjacent sequences:  A042869 A042870 A042871 * A042873 A042874 A042875

KEYWORD

nonn,cofr,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vincenzo Librandi, Dec 08 2013

STATUS

approved

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Last modified October 21 06:39 EDT 2019. Contains 328292 sequences. (Running on oeis4.)