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%I #14 Mar 18 2017 16:19:01
%S 25,26,77,180,797,3368,54685,58053,577162,1212377,1789539,22686845,
%T 115223764,137910609,253134373,391044982,1035224337,1426269319,
%U 5314032294,6740301613,12054333907,42903303334
%N Numerators of continued fraction convergents to sqrt(661).
%H Vincenzo Librandi, <a href="/A042270/b042270.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_78">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5730908870845166436, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F a(n) = 5730908870845166436*a(n-39) + a(n-78) for n>77. [_Bruno Berselli_, Nov 22 2013]
%t Numerator[Convergents[Sqrt[661], 30]] (* _Vincenzo Librandi_, Nov 20 2013 *)
%Y Cf. A042271.
%K nonn,cofr,frac,easy
%O 0,1
%A _N. J. A. Sloane_.