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 A295724 #6 Aug 27 2021 21:19:55
%S A295724 0,0,1,2,5,9,18,31,57,96,169,281,482,795,1341,2200,3669,5997,9922,
%T A295724 16175,26609,43296,70929,115249,188226,305523,497845,807464,1313501,
%U A295724 2129157,3459042,5604583,9096393,14733744,23895673,38694953,62721698,101547723,164531565
%N A295724 a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 0, a(1) = 0, a(2) = 1, a(3) = 2.
%C A295724 a(n)/a(n-1) -> (1 + sqrt(5))/2 = golden ratio (A001622), so that a( ) has the growth rate of the Fibonacci numbers (A000045).
%H A295724 Clark Kimberling, <a href="/A295724/b295724.txt">Table of n, a(n) for n = 0..2000</a>
%H A295724 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, -2, -2)
%F A295724 a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 0, a(1) = 0, a(2) = 1, a(3) = 2.
%F A295724 G.f.: (x^2 (1 + x))/((-1 + x + x^2) (-1 + 2 x^2)).
%t A295724 LinearRecurrence[{1, 3, -2, -2}, {0, 0, 1, 2}, 100]
%Y A295724 Cf. A001622, A000045, A005672.
%K A295724 nonn,easy
%O A295724 0,4
%A A295724 _Clark Kimberling_, Nov 29 2017