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 A295727 #6 Aug 27 2021 21:19:08
%S A295727 -1,1,1,1,4,3,11,10,29,31,76,91,199,258,521,715,1364,1951,3571,5266,
%T A295727 9349,14103,24476,37555,64079,99586,167761,263251,439204,694263,
%U A295727 1149851,1827730,3010349,4805311,7881196,12620971,20633239,33123138,54018521,86879515
%N A295727 a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = -1, a(1) = 1, a(2) = 1, a(3) = 1.
%C A295727 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 A295727 Clark Kimberling, <a href="/A295727/b295727.txt">Table of n, a(n) for n = 0..2000</a>
%H A295727 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, -2, -2)
%F A295727 a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = -1, a(1) = 1, a(2) = 1, a(3) = 1.
%F A295727 G.f.: (1 - 3 x)/(-1 + x + x^2) + x/(-1 + 2 x^2).
%t A295727 LinearRecurrence[{1, 3, -2, -2}, {-1, 1, 1, 1}, 100]
%Y A295727 Cf. A001622, A000045, A005672.
%K A295727 easy,sign
%O A295727 0,5
%A A295727 _Clark Kimberling_, Nov 29 2017