Constant term of the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments.

Terms

a(0) =1a(1) =0a(2) =2a(3) =5a(4) =13a(5) =28a(6) =56a(7) =105a(8) =189a(9) =330a(10) =564a(11) =949a(12) =1579a(13) =2606a(14) =4276a(15) =6987a(16) =11383a(17) =18506a(18) =30042a(19) =48719a(20) =78951a(21) =127880a(22) =207062a(23) =335195a(24) =542533a(25) =878028a(26) =1420886a(27) =2299265a(28) =3720529a(29) =6020200