G.f.: Sum_{n>=1} x^n * (1-x^n)^(n-1) / (1-x)^(n-1).

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =13a(6) =27a(7) =54a(8) =111a(9) =225a(10) =456a(11) =926a(12) =1877a(13) =3796a(14) =7671a(15) =15483a(16) =31212a(17) =62859a(18) =126484a(19) =254296a(20) =510892a(21) =1025765a(22) =2058395a(23) =4128578a(24) =8277344a(25) =16589180a(26) =33237163a(27) =66574351a(28) =133318484a(29) =266924608