This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A189736 #32 Jun 02 2025 04:04:13
%S A189736 3,2,12,40,144,512,1824,6496,23136,82400,293472,1045216,3722592,
%T A189736 13258208,47219808,168175840,598967136,2133253088,7597693536,
%U A189736 27059586784,96374147424,343241615840,1222473142368,4353902658784,15506654261088,55227768100832
%N A189736 a(1)=3, a(2)=2, a(n)=3*a(n-1) + 2*a(n-2).
%H A189736 Vincenzo Librandi, <a href="/A189736/b189736.txt">Table of n, a(n) for n = 1..100</a>
%H A189736 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,2).
%F A189736 G.f.: x*(3-7*x)/(1-3*x-2*x^2). - _Bruno Berselli_, May 24 2011
%t A189736 LinearRecurrence[{3,2},{3,2},40]
%o A189736 (Maxima) a[1]:3$ a[2]:2$ a[n]:=3*a[n-1]+2*a[n-2]$ makelist(a[n], n, 1, 26); /* _Bruno Berselli_, May 24 2011 */
%Y A189736 Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734, A189735, A189737, A189738, A189739, A189741, A189742, A189743, A189744, A189745, A189746, A189747, A189748, A189749.
%K A189736 nonn,easy
%O A189736 1,1
%A A189736 _Harvey P. Dale_, Apr 26 2011