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) =13a(5) =26a(6) =48a(7) =85a(8) =146a(9) =246a(10) =409a(11) =674a(12) =1104a(13) =1801a(14) =2930a(15) =4758a(16) =7717a(17) =12506a(18) =20256a(19) =32797a(20) =53090a(21) =85926a(22) =139057a(23) =225026a(24) =364128a(25) =589201a(26) =953378a(27) =1542630a(28) =2496061a(29) =4038746