%I #38 Nov 03 2021 06:08:49
%S 0,5,16,39,80,145,240,371,544,765,1040,1375,1776,2249,2800,3435,4160,
%T 4981,5904,6935,8080,9345,10736,12259,13920,15725,17680,19791,22064,
%U 24505,27120,29915,32896,36069,39440,43015,46800,50801,55024,59475,64160
%N a(n) = n*(n^2+4).
%C The identity (n^3+4*n)^2 + (2*n^2+8)^2 = (n^2+4)^3 can be written as a(n)^2 + A155966(n)^2 = A087475(n)^3.
%H Vincenzo Librandi, <a href="/A155965/b155965.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F G.f.: x*(5 - 4*x + 5*x^2)/(1 - x)^4. - _Vincenzo Librandi_, May 03 2014
%F a(n) = 4*a(n-1) - 6*a(n-2) +4*a(n-3) - a(n-4) for n>3. - _Vincenzo Librandi_, May 03 2014
%F a(n) = A006003(n-1) + A006003(n+1). - _Lechoslaw Ratajczak_, Oct 31 2021
%t Table[n (n^2 + 4), {n, 0, 100}] (* _Vladimir Joseph Stephan Orlovsky_, May 04 2011 *)
%t CoefficientList[Series[x (5 - 4 x + 5 x^2)/(1 - x)^4, {x, 0, 60}], x] (* _Vincenzo Librandi_, May 03 2014 *)
%t LinearRecurrence[{4,-6,4,-1},{0,5,16,39},50] (* _Harvey P. Dale_, Jan 23 2019 *)
%o (Sage) [lucas_number1(4,n,-2) for n in range(0, 41)] # _Zerinvary Lajos_, May 16 2009
%o (PARI) a(n)=n*(n^2+4) \\ _Charles R Greathouse IV_, Jan 11 2012
%Y Cf. A006003, A087475, A155966.
%K nonn,easy
%O 0,2
%A _Vincenzo Librandi_, Jan 31 2009