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) =1a(3) =3a(4) =7a(5) =16a(6) =33a(7) =64a(8) =118a(9) =210a(10) =364a(11) =619a(12) =1038a(13) =1723a(14) =2839a(15) =4653a(16) =7597a(17) =12370a(18) =20103a(19) =32626a(20) =52900a(21) =85716a(22) =138826a(23) =224773a(24) =363852a(25) =588901a(26) =953053a(27) =1542279a(28) =2495683a(29) =4038340