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 A322039 #11 Dec 04 2018 07:42:39
%S A322039 1,0,4,-4,16,-28,72,-148,336,-716,1560,-3332,7136,-15164,32168,-67956,
%T A322039 143216,-300972,631096,-1320420,2757376,-5747740,11961544,-24855124,
%U A322039 51574416,-106877068,221210712,-457334468,944495136,-1948642556
%N A322039 Expansion of (1 + x)^2 / ((1 - x)^2*(1 + 2*x)^2).
%C A322039 Connected with tiling of torus by squares (see A322038).
%H A322039 Colin Barker, <a href="/A322039/b322039.txt">Table of n, a(n) for n = 0..1000</a>
%H A322039 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (-2,3,4,-4).
%F A322039 From _Colin Barker_, Dec 04 2018: (Start)
%F A322039 a(n) = -2*a(n-1) + 3*a(n-2) + 4*a(n-3) - 4*a(n-4) for n>3.
%F A322039 a(n) = (16 + 11*(-2)^n + 3*(4+(-2)^n)*n) / 27.
%F A322039 (End)
%t A322039 LinearRecurrence[{-2, 3, 4, -4}, {1, 0, 4, -4}, 100] (* _Amiram Eldar_, Dec 04 2018 *)
%o A322039 (PARI) Vec((1 + x)^2 / ((1 - x)^2*(1 + 2*x)^2) + O(x^40)) \\ _Colin Barker_, Dec 04 2018
%Y A322039 Cf. A322038, A322040.
%K A322039 sign,easy
%O A322039 0,3
%A A322039 _N. J. A. Sloane_, Dec 03 2018