G.f.: A(x) = 1/(1 - x*B(x^2)), where B(x) = Sum_{n>=0} a(n)^2*x^n is the g.f. of A121648.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =8a(7) =16a(8) =27a(9) =51a(10) =89a(11) =170a(12) =300a(13) =564a(14) =1008a(15) =1972a(16) =3563a(17) =6847a(18) =12483a(19) =24340a(20) =44583a(21) =86071a(22) =158600a(23) =309554a(24) =572548a(25) =1108068a(26) =2057792a(27) =4003278a(28) =7451924a(29) =14415482