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 A295731 #6 Aug 27 2021 21:02:57
%S A295731 -1,-1,0,1,5,10,23,41,80,137,249,418,731,1213,2072,3413,5741,9410,
%T A295731 15663,25585,42272,68881,113201,184130,301427,489653,799272,1297117,
%U A295731 2112773,3426274,5571815,9030857,14668208,23764601,38563881,62459554,101285579,164007277
%N A295731 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) = 0, a(3) = 1.
%C A295731 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 A295731 Clark Kimberling, <a href="/A295731/b295731.txt">Table of n, a(n) for n = 0..2000</a>
%H A295731 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, -2, -2)
%F A295731 a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = -1, a(1) = -1, a(2) = 0, a(3) = 1.
%F A295731 G.f.: (-1 + 4 x^2 + 2 x^3)/(1 - x - 3 x^2 + 2 x^3 + 2 x^4).
%t A295731 LinearRecurrence[{1, 3, -2, -2}, {-1, -1, 0, 1}, 100]
%Y A295731 Cf. A001622, A000045, A005672.
%K A295731 easy,sign
%O A295731 0,5
%A A295731 _Clark Kimberling_, Nov 30 2017