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 A290916 #4 Aug 18 2017 21:34:55
%S A290916 0,1,4,18,84,387,1784,8228,37944,174981,806940,3721270,17160940,
%T A290916 79139079,364956336,1683025992,7761412016,35792386313,165059516916,
%U A290916 761185462362,3510269016516,16187892672139,74651791054120,344262840164460,1587596244438120
%N A290916 a(n) = (1/8)*A290915(n).
%H A290916 Clark Kimberling, <a href="/A290916/b290916.txt">Table of n, a(n) for n = 0..1000</a>
%H A290916 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4, 2, 4, -1)
%F A290916 G.f.: x/(1 - 4 x - 2 x^2 - 4 x^3 + x^4).
%F A290916 a(n) = 4*a(n-1) + 2*a(n-2) + 4*a(n-3) - a(n-4).
%F A290916 a(n) = (1/8)*A290915(n) for n >= 0.
%t A290916 z = 60; s = x/(1 - x)^2; p = 1 - 8 s^2;
%t A290916 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
%t A290916 u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290915 *)
%t A290916 u/8 (* A290916 *)
%Y A290916 Cf. A000027, A290890, A290915.
%K A290916 nonn,easy
%O A290916 0,3
%A A290916 _Clark Kimberling_, Aug 18 2017