G.f.: Sum_{n>=0} (x^n - 1)^n * x^n / (1-x)^(n+1).

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =1a(5) =-2a(6) =-3a(7) =1a(8) =9a(9) =13a(10) =6a(11) =-13a(12) =-33a(13) =-39a(14) =-18a(15) =33a(16) =102a(17) =159a(18) =158a(19) =46a(20) =-199a(21) =-525a(22) =-781a(23) =-744a(24) =-221a(25) =808a(26) =2089a(27) =3101a(28) =3212a(29) =1933