Expansion of Product_{m>=1} (1 + m*q^m)^4.

Terms

a(0) =1a(1) =4a(2) =14a(3) =48a(4) =137a(5) =380a(6) =998a(7) =2488a(8) =5996a(9) =14020a(10) =31868a(11) =70616a(12) =153389a(13) =326248a(14) =681914a(15) =1402880a(16) =2841769a(17) =5678316a(18) =11201956a(19) =21833480a(20) =42081245a(21) =80264752a(22) =151572328a(23) =283577152a(24) =525894397a(25) =967100700a(26) =1764378830a(27) =3194682272a(28) =5742739237a(29) =10252117308