%I #30 Jan 01 2024 11:07:27
%S 2,6,35,234,1598,10947,75026,514230,3524579,24157818,165580142,
%T 1134903171,7778742050,53316291174,365435296163,2504730781962,
%U 17167680177566,117669030460995,806515533049394,5527939700884758,37889062373143907,259695496911122586
%N a(n) = Fibonacci(4n+1) + 1, or Fibonacci(2n+1)*Lucas(2n).
%D Hugh C. Williams, Edouard Lucas and Primality Testing, John Wiley and Sons, 1998, p. 75
%H Nathaniel Johnston, <a href="/A081003/b081003.txt">Table of n, a(n) for n = 0..400</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (8,-8,1).
%F a(n) = 8*a(n-1) - 8*a(n-2) + a(n-3).
%F G.f.: (2-10*x+3*x^2)/((1-x)*(1-7*x+x^2)). - _Colin Barker_, Jun 24 2012
%p with(combinat): for n from 0 to 30 do printf(`%d,`,fibonacci(4*n+1)+1) od: # _James A. Sellers_, Mar 03 2003
%t Fibonacci[4*Range[0,30]+1]+1 (* or *) LinearRecurrence[{8,-8,1}, {2,6,35}, 30] (* _Harvey P. Dale_, Jul 20 2011 *)
%o (Magma) [Fibonacci(4*n+1) +1: n in [0..30]]; // _Vincenzo Librandi_, Apr 15 2011
%o (PARI) vector(30, n, n--; fibonacci(4*n+1)+1) \\ _G. C. Greubel_, Jul 15 2019
%o (Sage) [fibonacci(4*n+1)+1 for n in (0..30)] # _G. C. Greubel_, Jul 15 2019
%o (GAP) List([0..30], n-> Fibonacci(4*n+1)+1); # _G. C. Greubel_, Jul 15 2019
%Y Cf. A000045 (Fibonacci numbers), A000032 (Lucas numbers).
%K nonn,easy
%O 0,1
%A _R. K. Guy_, Mar 01 2003
%E More terms from _James A. Sellers_, Mar 03 2003