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 A077826 #13 May 12 2024 03:26:10
%S A077826 1,3,10,32,101,319,1006,3172,10001,31531,99410,313416,988125,3115319,
%T A077826 9821846,30965900,97627977,307797347,970410426,3059468848,9645763669,
%U A077826 30410754735,95877738174,302279267892,953013259777,3004619799579,9472837914274,29865561746840
%N A077826 Expansion of (1-x)^(-1)/(1-2*x-3*x^2-2*x^3).
%H A077826 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,1,-1,-2).
%F A077826 From _Wesley Ivan Hurt_, Jun 26 2022: (Start)
%F A077826 G.f.: (1-x)^(-1)/(1-2*x-3*x^2-2*x^3).
%F A077826 a(n) = 3*a(n-1) + a(n-2) - a(n-3) - 2*a(n-4). (End)
%t A077826 LinearRecurrence[{3,1,-1,-2},{1,3,10,32},30] (* _Harvey P. Dale_, May 12 2024 *)
%o A077826 (PARI) Vec((1-x)^(-1)/(1-2*x-3*x^2-2*x^3)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012
%Y A077826 Partial sums of S(n, x), for x=1...10, A021823, A000217, A027941, A061278, A089817, A053142, A092521, A076765, A092420, A097784.
%Y A077826 Partial sums of A077833.
%K A077826 nonn,easy
%O A077826 0,2
%A A077826 _N. J. A. Sloane_, Nov 17 2002