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A041885 Denominators of continued fraction convergents to sqrt(464). 2
1, 1, 2, 11, 13, 24, 37, 209, 246, 455, 19356, 19811, 39167, 215646, 254813, 470459, 725272, 4096819, 4822091, 8918910, 379416311, 388335221, 767751532, 4227092881, 4994844413, 9221937294, 14216781707, 80305845829, 94522627536, 174828473365, 7437318508866 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

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, 19602, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: -(x^18 -x^17 +2*x^16 -11*x^15 +13*x^14 -24*x^13 +37*x^12 -209*x^11 +246*x^10 -455*x^9 -246*x^8 -209*x^7 -37*x^6 -24*x^5 -13*x^4 -11*x^3 -2*x^2 -x -1) / ((x^10 -140*x^5 -1)*(x^10 +140*x^5 -1)). - Colin Barker, Nov 26 2013

a(n) = 19602*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 26 2013

MATHEMATICA

Denominator[Convergents[Sqrt[464], 30]] (* Vincenzo Librandi, Dec 26 2013 *)

PROG

(MAGMA) I:=[1, 1, 2, 11, 13, 24, 37, 209, 246, 455, 19356, 19811, 39167, 215646, 254813, 470459, 725272, 4096819, 4822091, 8918910]; [n le 20 select I[n] else 19602*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 26 2013

CROSSREFS

Cf. A041884, A040442.

Sequence in context: A090430 A022115 A042453 * A247338 A154742 A257329

Adjacent sequences:  A041882 A041883 A041884 * A041886 A041887 A041888

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 26 2013

STATUS

approved

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Last modified May 21 14:51 EDT 2019. Contains 323443 sequences. (Running on oeis4.)