G.f.: Sum_{n=-oo..+oo} x^n * (1 - 2^n*x^n)^n.

Terms

a(0) =-1a(1) =-3a(2) =7a(3) =-15a(4) =89a(5) =-63a(6) =121a(7) =-255a(8) =3521a(9) =-13119a(10) =18273a(11) =-4095a(12) =-40319a(13) =-16383a(14) =425089a(15) =-2676735a(16) =6141953a(17) =-262143a(18) =-22487551a(19) =-1048575a(20) =173791233a(21) =-356171775a(22) =176138241a(23) =-16777215a(24) =2378907649a(25) =-5430575103a(26) =3355336705a(27) =-38913703935a(28) =164745740289a(29) =-1073741823