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

Terms

a(0) =1a(1) =2a(2) =0a(3) =4a(4) =-3a(5) =6a(6) =-3a(7) =8a(8) =-15a(9) =28a(10) =-24a(11) =12a(12) =0a(13) =14a(14) =-48a(15) =96a(16) =-95a(17) =18a(18) =55a(19) =20a(20) =-180a(21) =232a(22) =-120a(23) =24a(24) =-35a(25) =76a(26) =-168a(27) =460a(28) =-580a(29) =30