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 A146005 #22 Sep 08 2022 08:45:38
%S A146005 0,1,6,12,28,55,108,203,376,684,1230,2189,3864,6773,11802,20460,35312,
%T A146005 60707,104004,177631,302540,513996,871266,1473817,2488368,4194025,
%U A146005 7057518,11858508,19898116,33345679,55814940,93320819,155867104
%N A146005 a(n) = n*Lucas(n).
%H A146005 Vincenzo Librandi, <a href="/A146005/b146005.txt">Table of n, a(n) for n = 0..1000</a>
%H A146005 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-2,-1).
%F A146005 a(n) = n*A000032(n).
%F A146005 G.f.: x(1+4x-x^2)/(1-x-x^2)^2.
%F A146005 a(n) = 2*a(n-1)+a(n-2)-2*a(n-3)-a(n-4).
%F A146005 a(n) = A000045(n)-5*A000045(n+1)+5*A010049(n+1).
%F A146005 a(n) = A045925(n)+2*A099920(n-1).
%F A146005 E.g.f.: x*exp(x/2)*(cosh(sqrt(5)*x/2) + sqrt(5)*sinh(sqrt(5)*x/2)). - _G. C. Greubel_, Jan 30 2016
%t A146005 Table[LucasL[n, 1]*n, {n, 0, 36}] (* _Zerinvary Lajos_, Jul 09 2009 *)
%t A146005 CoefficientList[Series[x * (1 + 4*x - x^2)/(1 - x - x^2)^2, {x, 0, 40}], x] (* _Vincenzo Librandi_, Dec 13 2012 *)
%t A146005 LinearRecurrence[{2,1,-2,-1},{0,1,6,12},40] (* _Harvey P. Dale_, Apr 03 2013 *)
%o A146005 (Magma) I:=[0, 1, 6, 12]; [n le 4 select I[n] else 2*Self(n-1) + Self(n-2) - 2*Self(n-3) - Self(n-4): n in [1..40]]; // _Vincenzo Librandi_, Dec 13 2012
%K A146005 easy,nonn
%O A146005 0,3
%A A146005 _R. J. Mathar_, Oct 26 2008