G.f.: 1 / Product_{k>=1} (1-x^k)^(k-1).

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =4a(5) =6a(6) =12a(7) =18a(8) =33a(9) =52a(10) =88a(11) =138a(12) =229a(13) =354a(14) =568a(15) =880a(16) =1378a(17) =2110a(18) =3260a(19) =4942a(20) =7527a(21) =11320a(22) =17031a(23) =25394a(24) =37842a(25) =55956a(26) =82630a(27) =121300a(28) =177677a(29) =258980