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) =0a(3) =3a(4) =10a(5) =27a(6) =60a(7) =121a(8) =228a(9) =411a(10) =718a(11) =1227a(12) =2064a(13) =3433a(14) =5664a(15) =9291a(16) =15178a(17) =24723a(18) =40188a(19) =65233a(20) =105780a(21) =171411a(22) =277630a(23) =449523a(24) =727680a(25) =1177777a(26) =1906080a(27) =3084531a(28) =4991338a(29) =8076651