Expansion of Product_{m>=1} (1 + m*q^m)^3.

Terms

a(0) =1a(1) =3a(2) =9a(3) =28a(4) =69a(5) =174a(6) =413a(7) =933a(8) =2046a(9) =4391a(10) =9168a(11) =18675a(12) =37522a(13) =73725a(14) =142893a(15) =273159a(16) =514512a(17) =957666a(18) =1762837a(19) =3208884a(20) =5783727a(21) =10330732a(22) =18280590a(23) =32086827a(24) =55880614a(25) =96579240a(26) =165733335a(27) =282513246a(28) =478419366a(29) =805196022