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A041641 Denominators of continued fraction convergents to sqrt(339). 2
1, 2, 5, 12, 17, 301, 318, 937, 2192, 5321, 193748, 392817, 979382, 2351581, 3330963, 58977952, 62308915, 183595782, 429500479, 1042596740, 37962983119, 76968562978, 191900109075, 460768781128, 652668890203, 11556139914579, 12208808804782 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index to sequences with linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,195940,0,0,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^18 -2*x^17 +5*x^16 -12*x^15 +17*x^14 -301*x^13 +318*x^12 -937*x^11 +2192*x^10 -5321*x^9 -2192*x^8 -937*x^7 -318*x^6 -301*x^5 -17*x^4 -12*x^3 -5*x^2 -2*x -1) / (x^20 -195940*x^10 +1). - Colin Barker, Nov 20 2013

a(n) = 195940*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 22 2013

MATHEMATICA

Denominator[Convergents[Sqrt[339], 30]] (* Vincenzo Librandi, Dec 22 2013 *)

PROG

I:=[1, 2, 5, 12, 17, 301, 318, 937, 2192, 5321, 193748, 392817, 979382, 2351581, 3330963, 58977952, 62308915, 183595782, 429500479, 1042596740]; [n le 20 select I[n] else 195940*Self(n-10) - Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013

CROSSREFS

Cf. A041640, A040320.

Sequence in context: A055906 A002355 A085395 * A131091 A116728 A095306

Adjacent sequences:  A041638 A041639 A041640 * A041642 A041643 A041644

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 20 2013

STATUS

approved

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Last modified April 18 07:04 EDT 2014. Contains 240706 sequences.