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 A290914 #6 May 05 2019 13:20:31
%S A290914 0,1,4,17,76,336,1484,6559,28988,128111,566184,2502240,11058600,
%T A290914 48873265,215994436,954583169,4218761572,18644733936,82400035556,
%U A290914 364165339279,1609421566844,7112807014943,31434910948176,138925971735744,613980604384080,2713475226049825
%N A290914 a(n) = (1/7)*A290913(n).
%H A290914 Clark Kimberling, <a href="/A290914/b290914.txt">Table of n, a(n) for n = 0..1000</a>
%H A290914 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4, 1, 4, -1)
%F A290914 G.f.: x/(1 - 4 x - x^2 - 4 x^3 + x^4).
%F A290914 a(n) = 4*a(n-1) + a(n-2) + 4*a(n-3) - a(n-4).
%F A290914 a(n) = (1/7)*A290913(n) for n >= 0.
%t A290914 z = 60; s = x/(1 - x)^2; p = 1 - 7 s^2;
%t A290914 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
%t A290914 u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290913 *)
%t A290914 u/7 (* A290914 *)
%t A290914 LinearRecurrence[{4,1,4,-1},{0,1,4,17},30] (* _Harvey P. Dale_, May 05 2019 *)
%Y A290914 Cf. A000027, A290890, A290913.
%K A290914 nonn,easy
%O A290914 0,3
%A A290914 _Clark Kimberling_, Aug 18 2017