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 A041811 Denominators of continued fraction convergents to sqrt(426). 2

%I

%S 1,1,2,3,11,25,161,347,1202,1549,2751,4300,174751,179051,353802,

%T 532853,1952361,4437575,28577811,61593197,213357402,274950599,

%U 488308001,763258600,31018652001,31781910601,62800562602,94582473203,346547982211,787678437625

%N Denominators of continued fraction convergents to sqrt(426).

%H Vincenzo Librandi, <a href="/A041811/b041811.txt">Table of n, a(n) for n = 0..200</a>

%H <a href="/index/Rec#order_24">Index entries for linear recurrences with constant coefficients</a>, 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).

%F 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

%F a(n) = 177502*a(n-12) - a(n-24) for n>23. - _Vincenzo Librandi_, Dec 24 2013

%t Denominator[Convergents[Sqrt[426], 30]] (* _Harvey P. Dale_, Apr 13 2012 *)

%t 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 *)

%Y Cf. A041810, A040405.

%K nonn,easy,frac

%O 0,3

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Nov 25 2013

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Last modified April 20 09:59 EDT 2019. Contains 322309 sequences. (Running on oeis4.)