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A041811 Denominators of continued fraction convergents to sqrt(426). 2
1, 1, 2, 3, 11, 25, 161, 347, 1202, 1549, 2751, 4300, 174751, 179051, 353802, 532853, 1952361, 4437575, 28577811, 61593197, 213357402, 274950599, 488308001, 763258600, 31018652001, 31781910601, 62800562602, 94582473203, 346547982211, 787678437625 (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, 0, 0, 177502, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: -(x^22 -x^21 +2*x^20 -3*x^19 +11*x^18 -25*x^17 +161*x^16 -347*x^15 +1202*x^14 -1549*x^13 +2751*x^12 -4300*x^11 -2751*x^10 -1549*x^9 -1202*x^8 -347*x^7 -161*x^6 -25*x^5 -11*x^4 -3*x^3 -2*x^2 -x -1) / (x^24 -177502*x^12 +1). - Colin Barker, Nov 25 2013

a(n) = 177502*a(n-12) - a(n-24) for n>23. - Vincenzo Librandi, Dec 24 2013

MATHEMATICA

Denominator[Convergents[Sqrt[426], 30]] (* Harvey P. Dale, Apr 13 2012 *)

CoefficientList[Series[-(x^22 - x^21 + 2 x^20 - 3 x^19 + 11 x^18 - 25 x^17 + 161 x^16 - 347 x^15 + 1202 x^14 - 1549 x^13 + 2751 x^12 - 4300 x^11 - 2751 x^10 - 1549 x^9 - 1202 x^8 - 347 x^7 - 161 x^6 - 25 x^5 - 11 x^4 - 3 x^3 - 2 x^2 - x - 1)/(x^24 - 177502 x^12 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 24 2013 *)

CROSSREFS

Cf. A041810, A040405.

Sequence in context: A041955 A239445 A157161 * A229066 A248161 A056851

Adjacent sequences:  A041808 A041809 A041810 * A041812 A041813 A041814

KEYWORD

nonn,easy,frac

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 25 2013

STATUS

approved

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Last modified March 21 20:16 EDT 2019. Contains 321382 sequences. (Running on oeis4.)