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

Terms

a(0) =1a(1) =2a(2) =-1a(3) =4a(4) =-1a(5) =6a(6) =-6a(7) =8a(8) =2a(9) =12a(10) =-15a(11) =12a(12) =8a(13) =14a(14) =-28a(15) =32a(16) =22a(17) =18a(18) =-55a(19) =20a(20) =34a(21) =72a(22) =-66a(23) =24a(24) =44a(25) =28a(26) =-91a(27) =140a(28) =62a(29) =30