G.f. A(x) satisfies A(x^2)^3/A(x^4)^3 = 1 + (A(x)/A(x^4) - 1)^2.

Terms

a(0) =1a(1) =3a(2) =0a(3) =3a(4) =3a(5) =0a(6) =0a(7) =-3a(8) =0a(9) =21a(10) =0a(11) =0a(12) =3a(13) =-39a(14) =0a(15) =0a(16) =3a(17) =45a(18) =0a(19) =141a(20) =0a(21) =-210a(22) =0a(23) =-450a(24) =0a(25) =1335a(26) =0a(27) =-258a(28) =-3a(29) =-2385