%I #19 Feb 09 2020 12:05:53

%S 1,1,2,6,14,32,72,160,354,782,1726,3808,8400,18528,40866,90134,198798,

%T 438464,967064,2132928,4704322,10375710,22884350,50473024,111321760,

%U 245527872,541528770,1194379302,2634286478,5810101728,12814582760,28263452000,62337005730,137488594222,303240640446

%N Expansion of (1 - 2*x + x^2 + x^3 + x^5) / ((1 - x)*(1 - 2*x - x^3)).

%H Colin Barker, <a href="/A232230/b232230.txt">Table of n, a(n) for n = 0..1000</a>

%H A. Goupil, M.-E. Pellerin and J. de Wouters d'Oplinter, <a href="http://arxiv.org/abs/1307.8432">Snake Polyominoes</a>, arXiv preprint arXiv:1307.8432 [math.CO], 2013-2014.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2,1,-1).

%F a(n) = 3*a(n-1) - 2*a(n-2) + a(n-3) - a(n-4) for n>3. - _Colin Barker_, Dec 05 2018

%F a(n) = 2*a(n-1) + a(n-3) + 2 for n>4. - _Greg Dresden_, Feb 09 2020

%t Join[{1, 1}, LinearRecurrence[{3, -2, 1, -1}, {2, 6, 14, 32}, 33]] (* _Jean-François Alcover_, Dec 05 2018 *)

%o (PARI) Vec((1 - 2*x + x^2 + x^3 + x^5) / ((1 - x)*(1 - 2*x - x^3)) + O(x^40)) \\ _Colin Barker_, Dec 05 2018

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_, Nov 23 2013