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) =10a(4) =29a(5) =70a(6) =148a(7) =289a(8) =534a(9) =950a(10) =1645a(11) =2794a(12) =4680a(13) =7761a(14) =12778a(15) =20930a(16) =34157a(17) =55598a(18) =90332a(19) =146577a(20) =237630a(21) =385006a(22) =623517a(23) =1009490a(24) =1634064a(25) =2644705a(26) =4280018a(27) =6926074a(28) =11207549a(29) =18135190