G.f.: ( Sum_{n>=0} 8^n*x^(n^2) )^(1/4).

Terms

a(0) =1a(1) =2a(2) =-6a(3) =28a(4) =-138a(5) =828a(6) =-5180a(7) =33528a(8) =-223002a(9) =1512812a(10) =-10423796a(11) =72743688a(12) =-513005252a(13) =3649850584a(14) =-26162987064a(15) =188758837488