Expansion of Product_{m>=1} (1+m*q^m)^-21.

Terms

a(0) =1a(1) =-21a(2) =189a(3) =-952a(4) =3087a(5) =-8400a(6) =27503a(7) =-92907a(8) =246981a(9) =-588490a(10) =1649823a(11) =-4645179a(12) =10989769a(13) =-25476717a(14) =65615424a(15) =-161705810a(16) =363998754a(17) =-834169539a(18) =1973130271a(19) =-4510112565a(20) =9969930495a(21) =-22054706773