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

Terms

a(0) =1a(1) =2a(2) =5a(3) =4a(4) =11a(5) =6a(6) =22a(7) =8a(8) =29a(9) =22a(10) =41a(11) =12a(12) =89a(13) =14a(14) =71a(15) =76a(16) =109a(17) =18a(18) =214a(19) =20a(20) =196a(21) =190a(22) =155a(23) =24a(24) =573a(25) =56a(26) =209a(27) =388a(28) =519a(29) =30