Expansion of Product_{m>=1} (1 + m*q^m)^2.

Terms

a(0) =1a(1) =2a(2) =5a(3) =14a(4) =28a(5) =64a(6) =133a(7) =266a(8) =513a(9) =1000a(10) =1873a(11) =3420a(12) =6257a(13) =11078a(14) =19585a(15) =34192a(16) =58714a(17) =99870a(18) =168858a(19) =281666a(20) =467082a(21) =768994a(22) =1253038a(23) =2030658a(24) =3269551a(25) =5227868a(26) =8304467a(27) =13133256a(28) =20630535a(29) =32250274