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%I #33 Jan 03 2024 23:46:42
%S 0,6,216,7770,279504,10054374,361677960,13010352186,468011000736,
%T 16835385674310,605605873274424,21784976052204954,783653532006103920,
%U 28189742176167536166,1014047064810025198056,36477504590984739593850
%N a(n+2) = 36*a(n+1) - a(n), a(1)=0, a(2)=6.
%C If a(n)=x and a(n+1)=y then (x^2+y^2)/(xy+1)=36.
%H Vincenzo Librandi, <a href="/A154023/b154023.txt">Table of n, a(n) for n = 1..500</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (36,-1).
%F From _R. J. Mathar_, Oct 18 2010: (Start)
%F a(n)= +36*a(n-1) -a(n-2)
%F a(n) = 6*A144128(n-1).
%F G.f.: 6*x/(1 -36*x +x^2). (End)
%t LinearRecurrence[{36,-1},{0,6},50] (* _Vincenzo Librandi_, Jan 30 2012 *)
%o (PARI) concat(0,Vec(6/(1-36*x+x^2)+O(x^98))) \\ _Charles R Greathouse IV_, Dec 27 2011
%Y Cf. A065100, A154021-A154027.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Jan 04 2009
%E Edited by _N. J. A. Sloane_, Jun 23 2010 at the suggestion of _Joerg Arndt_.
%E Missing digit inserted in a(8) by _R. J. Mathar_, Oct 18 2010
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