a(n) = [x^n] Product_{k>=1} (1 - k*x^k)^n.

Terms

a(0) =1a(1) =-1a(2) =-3a(3) =8a(4) =9a(5) =-26a(6) =-168a(7) =489a(8) =1041a(9) =-5599a(10) =12a(11) =27103a(12) =23436a(13) =-222912a(14) =-435473a(15) =3177433a(16) =375569a(17) =-24956018a(18) =6931209a(19) =181844002a(20) =57372644a(21) =-2158209675a(22) =853739235a(23) =20642183588a(24) =-25063980804a(25) =-148768035501a(26) =224915906836