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 A262594 #8 Jul 04 2022 12:28:49
%S A262594 1,4,14,52,203,808,3232,12936,51765,207100,828466,3313964,13255999,
%T A262594 53024192,212097028,848388448,3393554217,13574217396,54296870230,
%U A262594 217187481700,868749927731,3474999712024,13899998849384,55599995399032,222399981597853,889599926393388,3558399705575802,14233598822305756
%N A262594 Expansion of (1-2*x)^2/((1-x)^4*(1-4*x)).
%C A262594 Suggested by A262592.
%H A262594 Colin Barker, <a href="/A262594/b262594.txt">Table of n, a(n) for n = 0..1000</a>
%H A262594 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (8,-22,28,-17,4).
%F A262594 From _Colin Barker_, Oct 23 2015: (Start)
%F A262594 a(n) = 8*a(n-1)-22*a(n-2)+28*a(n-3)-17*a(n-4)+4*a(n-5) for n>4.
%F A262594 a(n) = (34+2^(7+2*n)+93*n+18*n^2-9*n^3)/162.
%F A262594 (End)
%t A262594 CoefficientList[Series[(1-2x)^2/((1-x)^4(1-4x)),{x,0,40}],x] (* or *) LinearRecurrence[ {8,-22,28,-17,4},{1,4,14,52,203},40] (* _Harvey P. Dale_, Jul 04 2022 *)
%o A262594 (PARI) a(n) = (34+2^(7+2*n)+93*n+18*n^2-9*n^3)/162 \\ _Colin Barker_, Oct 23 2015
%o A262594 (PARI) Vec((1-2*x)^2/((1-x)^4*(1-4*x)) + O(x^40)) \\ _Colin Barker_, Oct 23 2015
%Y A262594 Cf. A262592.
%K A262594 nonn,easy
%O A262594 0,2
%A A262594 _N. J. A. Sloane_, Oct 22 2015