Expansion of Product_{m>=1} (1-m*q^m)^20.

Terms

a(0) =1a(1) =-20a(2) =150a(3) =-400a(4) =-875a(5) =7396a(6) =-7770a(7) =-36600a(8) =56510a(9) =154660a(10) =-872a(11) =-1314200a(12) =-455605a(13) =6284960a(14) =3781830a(15) =-9954864a(16) =-43558410a(17) =-16664680a(18) =165132890a(19) =229738040a(20) =57372644a(21) =-1326447180a(22) =-2095012310a(23) =1723402120a(24) =7805180205