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 A295725 #6 Aug 27 2021 21:19:41
%S A295725 0,0,-1,1,-2,3,-3,8,-3,21,2,55,25,144,105,377,354,987,1085,2584,3157,
%T A295725 6765,8898,17711,24561,46368,66833,121393,180034,317811,481461,832040,
%U A295725 1280733,2178309,3393506,5702887,8965321,14930352,23633529,39088169,62197410
%N A295725 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) = 1.
%C A295725 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 A295725 Clark Kimberling, <a href="/A295725/b295725.txt">Table of n, a(n) for n = 0..2000</a>
%H A295725 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, -2, -2)
%F A295725 a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 0, a(1) = 0, a(2) = -1, a(3) = 1.
%F A295725 G.f.: (-1 + x)/(-1 + x + x^2) + 1/(-1 + 2 x^2).
%t A295725 LinearRecurrence[{1, 3, -2, -2}, {0, 0, -1, 1}, 100]
%Y A295725 Cf. A001622, A000045, A005672.
%K A295725 easy,sign
%O A295725 0,5
%A A295725 _Clark Kimberling_, Nov 29 2017