%I #8 Jun 13 2015 00:51:49
%S 3,2,5,10,25,56,128,288,649,1459,3280,7371,16564,37220,83634,187925,
%T 422265,948822,2131985,4790528,10764220,24186984,54347661,122118087,
%U 274396852,616564131
%N a(n) = 3*a(n-1)-a(n-2)-2*a(n-3)+a(n-4), n>5.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3, -1, -2, 1).
%F G.f.: (-2*x^2-3*x^3+x^5-3+7*x-x^4)/( (x-1)*(x^3-x^2-2*x+1)) . [Sep 28 2009]
%t NSolve[x^3 - 2*x^2 - x + 1 == 0, x] b1 = -0.8019377358048383 b2 = 0.5549581320873712 b3 = 2.2469796037174667 digits = 25 a = Table[2*(b3^n + b1^n + b2^n)/ (b3 + b2 + b1), {n, 0, digits}] Floor[a]
%t LinearRecurrence[{3,-1,-2,1},{3,2,5,10,25,56},30] (* _Harvey P. Dale_, Jun 07 2015 *)
%K nonn,easy
%O 0,1
%A _Roger L. Bagula_, May 20 2005
%E Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009