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A041233 Denominators of continued fraction convergents to sqrt(128). 2
1, 3, 16, 51, 1138, 3465, 18463, 58854, 1313251, 3998607, 21306286, 67917465, 1515490516, 4614389013, 24587435581, 78376695756, 1748874742213, 5325000922395, 28373879354188, 90446638984959, 2018199937023286, 6145046450054817, 32743432187297371 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1154,0,0,0,-1).

FORMULA

G.f.: (1 +3*x +16*x^2 +51*x^3 -16*x^4 +3*x^5 -x^6)/(1 -1154*x^4 +x^8). - Vincenzo Librandi, Dec 13 2013

a(n) = 1154*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 13 2013

MATHEMATICA

Denominator[Convergents[Sqrt[128], 20]] (* Harvey P. Dale, Apr 01 2013 *)

CoefficientList[Series[(1 + 3 x + 16 x^2 + 51 x^3 - 16 x^4 + 3 x^5 - x^6)/(1 - 1154 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 13 2013 *)

PROG

(MAGMA) I:=[1, 3, 16, 51, 1138, 3465, 18463, 58854]; [n le 8 select I[n] else 1154*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 13 2013

CROSSREFS

Cf. A041232.

Sequence in context: A004320 A089363 A000574 * A055194 A190730 A173052

Adjacent sequences:  A041230 A041231 A041232 * A041234 A041235 A041236

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vincenzo Librandi, Dec 13 2013

STATUS

approved

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Last modified January 22 07:39 EST 2020. Contains 331139 sequences. (Running on oeis4.)