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 A153819 #25 Sep 08 2022 08:45:40
%S A153819 16,34,88,232,610,1600,4192,10978,28744,75256,197026,515824,1350448,
%T A153819 3535522,9256120,24232840,63442402,166094368,434840704,1138427746,
%U A153819 2980442536,7802899864,20428257058,53481871312,140017356880,366570199330,959693241112,2512509524008
%N A153819 Linear recurrence with a(n) = 3a(n-1) - a(n-2) + 2 = 4a(n-1) - 4a(n-2) + a(n-3). Full sequence for A153466.
%C A153819 a(n) mod 9 = 7.
%C A153819 A two-way infinite sequence with a(-n) = a(n-1).
%H A153819 G. C. Greubel, <a href="/A153819/b153819.txt">Table of n, a(n) for n = 0..1000</a>
%H A153819 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4,1).
%F A153819 G.f.: 2*(8-15*x+8*x^2)/((1-x)*(1-3*x+x^2)). - _Jaume Oliver Lafont_, Aug 30 2009
%F A153819 a(n) = 2*A153873(n) = 18*Fibonacci(2*n+1)-2.
%F A153819 a(n) = (2^(-n)*(-5*2^(1+n)-9*(3-sqrt(5))^n*(-5+sqrt(5))+9*(3+sqrt(5))^n*(5+sqrt(5))))/5. - _Colin Barker_, Nov 02 2016
%t A153819 LinearRecurrence[{4, -4, 1}, {16, 34, 88} , 100] (* _G. C. Greubel_, Jun 18 2016 *)
%o A153819 (Magma) [18*Fibonacci(2*n+1)-2: n in [0..30]]; // _Vincenzo Librandi_, Jun 19 2016
%o A153819 (PARI) Vec(2*(8-15*x+8*x^2)/((1-x)*(1-3*x+x^2)) + O(x^30)) \\ _Colin Barker_, Nov 02 2016
%K A153819 nonn,easy
%O A153819 0,1
%A A153819 _Paul Curtz_, Jan 02 2009
%E A153819 Edited by _Charles R Greathouse IV_, Oct 05 2009