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 A077822 #9 Jan 20 2024 17:12:17
%S A077822 1,4,16,63,246,960,3745,14608,56980,222255,866922,3381492,13189753,
%T A077822 51447580,200674984,782747199,3053161710,11909076696,46452209617,
%U A077822 181190182360,706745329324,2756710954287,10752749215554,41941871168172,163597283059753,638122961114884
%N A077822 Expansion of (1-x)^(-1)/(1-3*x-3*x^2-2*x^3).
%H A077822 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,0,-1,-2).
%F A077822 G.f.: (1-x)^(-1)/(1-3*x-3*x^2-2*x^3).
%F A077822 a(n) = 4*a(n-1) - a(n-3) - 2*a(n-4). - _Wesley Ivan Hurt_, Jan 20 2024
%t A077822 CoefficientList[Series[(1 - x)^(-1)/(1 - 3*x - 3*x^2 - 2*x^3), {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Jan 20 2024 *)
%Y A077822 Cf. A077829 (first differences).
%K A077822 nonn,easy
%O A077822 0,2
%A A077822 _N. J. A. Sloane_, Nov 17 2002