A041431 - OEIS

%I #13 Jun 13 2015 00:49:24

%S 1,5,151,760,22951,115515,3488401,17557520,530214001,2668627525,

%T 80589039751,405613826280,12249003828151,61650632967035,

%U 1861767992839201,9370490597163040,282976485907730401,1424252920135815045

%N Denominators of continued fraction convergents to sqrt(231).

%H Vincenzo Librandi, <a href="/A041431/b041431.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 (0,152,0,-1).

%F a(n) = 152*a(n-2)-a(n-4). G.f.: -(x^2-5*x-1)/(x^4-152*x^2+1). [_Colin Barker_, Jul 15 2012]

%t CoefficientList[Series[- (x^2 - 5 x - 1)/(x^4 - 152 x^2 + 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Oct 25 2013 *)

%Y Cf. A041430.

%K nonn,cofr,frac,easy

%O 0,2

%A _N. J. A. Sloane_.