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 A291385 #9 Sep 29 2022 16:15:29
%S A291385 1,4,14,47,152,480,1488,4548,13744,41152,122272,360944,1059584,
%T A291385 3095552,9005568,26101824,75404544,217191424,623928832,1788071680,
%U A291385 5113137152,14592352256,41569120256,118219097088,335685021696,951817715712,2695241605120,7622609858560
%N A291385 a(n) = (1/4)*A073388(n+1).
%H A291385 Clark Kimberling, <a href="/A291385/b291385.txt">Table of n, a(n) for n = 0..1000</a>
%H A291385 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,0,-8,-4)
%F A291385 G.f.: -(((1 + x) (-1 + x + x^2))/(-1 + 2 x + 2 x^2)^2).
%F A291385 a(n) = 4*a(n-1) - 8*a(n-3) + 4*a(n-4) for n >= 5.
%F A291385 a(n) = Sum_{k=0..n+1} k * A155112(n+1,k). - _Alois P. Heinz_, Sep 29 2022
%t A291385 z = 60; s = x + x^2; p = (1 - 2 s)^2;
%t A291385 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A019590 *)
%t A291385 u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A073388 *)
%t A291385 u / 2 (* A291385 *)
%t A291385 LinearRecurrence[{4,0,-8,-4},{1,4,14,47},30] (* _Harvey P. Dale_, Aug 24 2022 *)
%Y A291385 Cf. A019590, A291382, A073388, A155112.
%K A291385 nonn,easy
%O A291385 0,2
%A A291385 _Clark Kimberling_, Sep 04 2017