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%I #22 Jun 13 2015 00:49:21
%S 1,4,5,14,19,90,1279,5206,6485,18176,24661,116820,1660141,6757384,
%T 8417525,23592434,32009959,151632270,2154861739,8771079226,
%U 10925940965,30622961156,41548902121,196818569640,2797008877081,11384854077964,14181862955045,39748579988054
%N Denominators of continued fraction convergents to sqrt(52).
%H Vincenzo Librandi, <a href="/A041089/b041089.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,1298,0,0,0,0,0,-1).
%F a(n) = 1298*a(n-6)-a(n-12). G.f.: -(x^10-4*x^9+5*x^8-14*x^7+19*x^6-90*x^5-19*x^4-14*x^3-5*x^2-4*x-1)/((x^2-3*x-1)*(x^2+3*x-1)*(x^4-3*x^3+10*x^2+3*x+1)*(x^4+3*x^3+10*x^2-3*x+1)). [_Colin Barker_, Jul 18 2012]
%t Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[52], n]]], {n, 1, 50}] (* _Vladimir Joseph Stephan Orlovsky_, Jun 23 2011 *)
%t Denominator[Convergents[Sqrt[52], 30]] (* _Vincenzo Librandi_, Oct 24 2013 *)
%Y Cf. A010505, A041088.
%K nonn,cofr,frac,easy
%O 0,2
%A _N. J. A. Sloane_.