G.f.: A(x) = Sum_{n>=0} x^n / (1 - x^n - x^(2*n))^n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =6a(6) =17a(7) =14a(8) =36a(9) =44a(10) =81a(11) =90a(12) =225a(13) =234a(14) =456a(15) =682a(16) =1166a(17) =1598a(18) =2967a(19) =4182a(20) =7366a(21) =11215a(22) =18467a(23) =28658a(24) =48561a(25) =75216a(26) =123692a(27) =197415a(28) =322530a(29) =514230