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A189744 a(1)=4, a(2)=5, a(n) = 4*a(n-1) + 5*a(n-2).

%I A189744 #35 Feb 18 2024 08:28:52
%S A189744 4,5,40,185,940,4685,23440,117185,585940,2929685,14648440,73242185,
%T A189744 366210940,1831054685,9155273440,45776367185,228881835940,
%U A189744 1144409179685,5722045898440,28610229492185,143051147460940,715255737304685,3576278686523440,17881393432617185
%N A189744 a(1)=4, a(2)=5, a(n) = 4*a(n-1) + 5*a(n-2).
%H A189744 Vincenzo Librandi, <a href="/A189744/b189744.txt">Table of n, a(n) for n = 1..500</a>
%H A189744 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4,5).
%F A189744 G.f.: x*(4-11*x)/(1 - 4*x - 5*x^2). - _Bruno Berselli_, May 24 2011
%t A189744 LinearRecurrence[{4,5},{4,5},40]
%o A189744 (Maxima) a[1]:4$ a[2]:5$ a[n]:=4*a[n-1]+5*a[n-2]$ makelist(a[n], n, 1, 24); /* _Bruno Berselli_, May 24 2011 */
%o A189744 (Magma) [5/2*(-1)^(n-1)+3/2*5^(n-1): n in [1..30]]; // _Vincenzo Librandi_, Jul 15 2011
%o A189744 (PARI) a(n)=5/2*(-1)^(n-1)+3/2*5^(n-1) \\ _Charles R Greathouse IV_, Jul 02 2013
%Y A189744 Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734-A189739, A189741, A189742, A189743, A189745-A189749.
%K A189744 nonn,easy
%O A189744 1,1
%A A189744 _Harvey P. Dale_, Apr 26 2011