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

Terms

a(0) =1a(1) =-1a(2) =-4a(3) =9a(4) =48a(5) =100a(6) =-756a(7) =-3479a(8) =-1600a(9) =24462a(10) =225900a(11) =364573a(12) =-643536a(13) =-9251736a(14) =-36989316a(15) =-32397975a(16) =165039872a(17) =1725828525a(18) =5338814652a(19) =8082713829a(20) =-26321848400a(21) =-233434232766a(22) =-811526778964