Expansion of ( Sum_{n = -infinity..infinity} x^(n^2) )^(-9).

Terms

a(0) =1a(1) =-18a(2) =180a(3) =-1320a(4) =7902a(5) =-40824a(6) =188232a(7) =-792000a(8) =3088980a(9) =-11297546a(10) =39090312a(11) =-128849976a(12) =406865880a(13) =-1236379320a(14) =3629385936a(15) =-10324840512a(16) =28542038238a(17) =-76852151280a(18) =201967043260a(19) =-518957929080