G.f.: x^4*(6 + x - 7*x^2 - x^3 + 3*x^4 + x^5)/(1-x-x^2)^3.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =6a(5) =19a(6) =50a(7) =119a(8) =265a(9) =564a(10) =1160a(11) =2324a(12) =4559a(13) =8791a(14) =16710a(15) =31379a(16) =58314a(17) =107393a(18) =196216a(19) =355999a(20) =641879a(21) =1150878a(22) =2053132a(23) =3646042a(24) =6447949a(25) =11359823a(26) =19943772a(27) =34901845a(28) =60897678a(29) =105964063