G.f.: ( Sum_{n>=0} 8^n*x^(n^2) )^(1/2).

Terms

a(0) =1a(1) =4a(2) =-8a(3) =32a(4) =-128a(5) =768a(6) =-4608a(7) =28672a(8) =-184320a(9) =1212672a(10) =-8127488a(11) =55318528a(12) =-381329408a(13) =2656845824a(14) =-18680250368a(15) =132373807104a(16) =-944459216896