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A042427 Denominators of continued fraction convergents to sqrt(741). 2
1, 4, 5, 9, 122, 2205, 28787, 30992, 59779, 270108, 14645611, 58852552, 73498163, 132350715, 1794057458, 32425384959, 423324061925, 455749446884, 879073508809, 3972043482120, 215369421543289, 865449729655276, 1080819151198565, 1946268880853841 (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 (0,0,0,0,0,0,0,0,0,14705390,0,0,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^18 -4*x^17 +5*x^16 -9*x^15 +122*x^14 -2205*x^13 +28787*x^12 -30992*x^11 +59779*x^10 -270108*x^9 -59779*x^8 -30992*x^7 -28787*x^6 -2205*x^5 -122*x^4 -9*x^3 -5*x^2 -4*x -1) / (x^20 -14705390*x^10 +1). - Colin Barker, Dec 12 2013

a(n) = 14705390*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Jan 22 2014

MATHEMATICA

Denominator[Convergents[Sqrt[741], 30]] (* Harvey P. Dale, Dec 31 2012 *)

CoefficientList[Series[-(x^18 - 4 x^17 + 5 x^16 - 9 x^15 + 122 x^14 - 2205 x^13 + 28787 x^12 - 30992 x^11 + 59779 x^10 - 270108 x^9 - 59779 x^8 - 30992 x^7 - 28787 x^6 - 2205 x^5 - 122 x^4 - 9 x^3 - 5 x^2 - 4 x - 1)/(x^20 - 14705390 x^10 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 22 2014 *)

CROSSREFS

Cf. A042426, A040713.

Sequence in context: A041627 A132811 A042179 * A009778 A215754 A226486

Adjacent sequences:  A042424 A042425 A042426 * A042428 A042429 A042430

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 12 2013

STATUS

approved

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Last modified September 21 23:55 EDT 2019. Contains 327286 sequences. (Running on oeis4.)