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

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =14a(5) =30a(6) =59a(7) =110a(8) =197a(9) =343a(10) =585a(11) =983a(12) =1634a(13) =2695a(14) =4420a(15) =7220a(16) =11760a(17) =19116a(18) =31029a(19) =50316a(20) =81535a(21) =132061a(22) =213827a(23) =346141a(24) =560244a(25) =906685a(26) =1467254a(27) =2374290a(28) =3841922a(29) =6216618