Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #14 Sep 08 2022 08:44:54
%S 1,1,11,12,275,287,3145,3432,78649,82081,899459,981540,22493339,
%T 23474879,257242129,280717008,6433016305,6713733313,73570349435,
%U 80284082748,1839820169891,1920104252639,21040862696281,22960966948920,526182135572521,549143102521441
%N Denominators of continued fraction convergents to sqrt(142).
%H Vincenzo Librandi, <a href="/A041261/b041261.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 (0,0,0,286,0,0,0,-1).
%F G.f.: (1 +x +11*x^2 +12*x^3 -11*x^4 +x^5 -x^6)/(1 -286*x^4 +x^8). - _Vincenzo Librandi_, Dec 14 2013
%F a(n) = 286*a(n-4) - a(n-8). - _Vincenzo Librandi_, Dec 14 2013
%t Denominator[Convergents[Sqrt[142], 30]] (* or *) CoefficientList[Series[(1 + x + 11 x^2 + 12 x^3 - 11 x^4 + x^5 - x^6)/(1 - 286 x^4 + x^8), {x, 0, 30}], x] (* _Vincenzo Librandi_, Dec 14 2013 *)
%o (Magma) I:=[1,1,11,12,275,287,3145,3432]; [n le 8 select I[n] else 286*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 14 2013
%Y Cf. A041260.
%K nonn,frac,easy
%O 0,3
%A _N. J. A. Sloane_.
%E More terms from _Vincenzo Librandi_, Dec 14 2013