Expansion of (phi(-q) / phi(q^2))^2 in powers of q where phi() is a Ramanujan theta function.

Terms

a(0) =1a(1) =-4a(2) =0a(3) =16a(4) =0a(5) =-56a(6) =0a(7) =160a(8) =0a(9) =-404a(10) =0a(11) =944a(12) =0a(13) =-2072a(14) =0a(15) =4320a(16) =0a(17) =-8648a(18) =0a(19) =16720a(20) =0a(21) =-31360a(22) =0a(23) =57312a(24) =0a(25) =-102364a(26) =0a(27) =179104a(28) =0a(29) =-307672