G.f.: Sum_{n>=0} x^n * (1 + x^n)^n / (1 - x^(n+1))^(n+1).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =9a(7) =16a(8) =16a(9) =18a(10) =36a(11) =34a(12) =27a(13) =68a(14) =76a(15) =58a(16) =86a(17) =122a(18) =170a(19) =176a(20) =99a(21) =206a(22) =436a(23) =350a(24) =192a(25) =392a(26) =574a(27) =690a(28) =840a(29) =730