Expansion of g.f. (1+x)*Product_{m>0} (1 + x^m).

Terms

a(0) =1a(1) =2a(2) =2a(3) =3a(4) =4a(5) =5a(6) =7a(7) =9a(8) =11a(9) =14a(10) =18a(11) =22a(12) =27a(13) =33a(14) =40a(15) =49a(16) =59a(17) =70a(18) =84a(19) =100a(20) =118a(21) =140a(22) =165a(23) =193a(24) =226a(25) =264a(26) =307a(27) =357a(28) =414a(29) =478