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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =5a(5) =9a(6) =14a(7) =22a(8) =35a(9) =55a(10) =88a(11) =138a(12) =219a(13) =347a(14) =548a(15) =868a(16) =1373a(17) =2173a(18) =3438a(19) =5440a(20) =8609a(21) =13621a(22) =21554a(23) =34106a(24) =53967a(25) =85395a(26) =135124a(27) =213814a(28) =338327a(29) =535351