Constant term in the reduction of the n-th Fibonacci polynomial by x^3->x^2+x+1. See Comments.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =2a(5) =6a(6) =10a(7) =29a(8) =57a(9) =142a(10) =309a(11) =720a(12) =1625a(13) =3714a(14) =8457a(15) =19259a(16) =43902a(17) =99970a(18) =227830a(19) =518943a(20) =1182401a(21) =2693624a(22) =6136837a(23) =13980960a(24) =31851853a(25) =72565704a(26) =165320833a(27) =376638417a(28) =858066430a(29) =1954869262