|
%I #9 Jun 13 2015 00:50:28
%S 0,4,12,34,108,344,1104,3546,11396,36628,117732,378426,1216380,
%T 3909832,12567448,40395794,129844996,417363332,1341539196,4312135922,
%U 13860583628,44552347608,143205490528,460308235562,1479577849604
%N G.f.: 2*x*(2-2*x-3*x^2+2*x^3)/((1-3*x-x^2+x^3)*(1-x)).
%D R. P. Stanley, Enumerative Combinatorics I, Example 4.7.17.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-2,-2,1)
%Y Row sums of A061702, A000183.
%K easy,nonn
%O 0,2
%A _Vladeta Jovovic_, Jun 18 2001
|
