G.f.: Sum_{n=-oo..+oo, n<>0} x^(n^2) / (1 - x^n)^(n+1).

Terms

a(0) =2a(1) =1a(2) =4a(3) =5a(4) =6a(5) =6a(6) =8a(7) =16a(8) =12a(9) =15a(10) =12a(11) =32a(12) =14a(13) =28a(14) =32a(15) =52a(16) =18a(17) =55a(18) =20a(19) =74a(20) =72a(21) =66a(22) =24a(23) =160a(24) =28a(25) =91a(26) =140a(27) =146a(28) =30a(29) =205