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 A199802 #16 Jan 05 2025 19:51:39
%S A199802 1,2,2,1,-1,-4,-7,-8,-5,3,15,27,32,22,-8,-55,-104,-128,-95,17,200,399,
%T A199802 510,405,-11,-721,-1525,-2024,-1708,-172,2573,5806,8002,7137,1503,
%U A199802 -9072,-22015,-31520,-29585,-9073,31519,83119,123712,121778,47732,-107499,-312396,-483840,-498119,-233455,357884,1168399,1885694,2025929,1090985,-1152593
%N A199802 G.f.: 1/(1-2*x+2*x^2-x^3+x^4).
%H A199802 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 G_n.
%H A199802 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (2,-2,1,-1).
%t A199802 CoefficientList[Series[1/(1-2x+2x^2-x^3+x^4),{x,0,60}],x] (* or *) LinearRecurrence[ {2,-2,1,-1},{1,2,2,1},60] (* _Harvey P. Dale_, May 11 2022 *)
%Y A199802 The main sequences mentioned in the Hisrchhorn paper are A199802, A199803, A199744, A199804, A077961, A199805.
%K A199802 sign,easy
%O A199802 0,2
%A A199802 _N. J. A. Sloane_, Nov 10 2011