Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #23 Jan 05 2025 19:51:39
%S 2,-4,-5,27,-8,-128,200,405,-1525,-172,8002,-9072,-29585,83119,47732,
%T -483840,357884,2025929,-4346921,-4941000,28343650,-10011500,
%U -132300829,215642979,407506016,-1608010240,-81576032,8313490269,-9921126365,-30119890772,88120588898,44244248328,-505045957225
%N Trisection 2 of A199802.
%H Colin Barker, <a href="/A199929/b199929.txt">Table of n, a(n) for n = 0..1000</a>
%H 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 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-5,1,-1).
%F From _Colin Barker_, Dec 27 2017: (Start)
%F G.f.: (2 - 2*x + x^2) / (1 + x + 5*x^2 - x^3 + x^4).
%F a(n) = -a(n-1) - 5*a(n-2) + a(n-3) - a(n-4) for n>3.
%F (End)
%t LinearRecurrence[{-1,-5,1,-1},{2,-4,-5,27},40] (* _Harvey P. Dale_, May 26 2018 *)
%o (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 Cf. A199802.
%K sign,easy
%O 0,1
%A _N. J. A. Sloane_, Nov 12 2011