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 A199929 #23 Jan 05 2025 19:51:39
%S A199929 2,-4,-5,27,-8,-128,200,405,-1525,-172,8002,-9072,-29585,83119,47732,
%T A199929 -483840,357884,2025929,-4346921,-4941000,28343650,-10011500,
%U A199929 -132300829,215642979,407506016,-1608010240,-81576032,8313490269,-9921126365,-30119890772,88120588898,44244248328,-505045957225
%N A199929 Trisection 2 of A199802.
%H A199929 Colin Barker, <a href="/A199929/b199929.txt">Table of n, a(n) for n = 0..1000</a>
%H A199929 Hirschhorn, Michael D., <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/43-4.html">Non-trivial intertwined second-order recurrence relations</a>, Fibonacci Quart. 43 (2005), no. 4, 316-325. See p. 324.
%H A199929 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-5,1,-1).
%F A199929 From _Colin Barker_, Dec 27 2017: (Start)
%F A199929 G.f.: (2 - 2*x + x^2) / (1 + x + 5*x^2 - x^3 + x^4).
%F A199929 a(n) = -a(n-1) - 5*a(n-2) + a(n-3) - a(n-4) for n>3.
%F A199929 (End)
%t A199929 LinearRecurrence[{-1,-5,1,-1},{2,-4,-5,27},40] (* _Harvey P. Dale_, May 26 2018 *)
%o A199929 (PARI) Vec((2 - 2*x + x^2) / (1 + x + 5*x^2 - x^3 + x^4) + O(x^40)) \\ _Colin Barker_, Dec 27 2017
%Y A199929 Cf. A199802.
%K A199929 sign,easy
%O A199929 0,1
%A A199929 _N. J. A. Sloane_, Nov 12 2011