G.f. A(x) satisfies A(x) = 1 + x^4*(1+x)*A(x)^3.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =3a(9) =6a(10) =3a(11) =0a(12) =12a(13) =36a(14) =36a(15) =12a(16) =55a(17) =220a(18) =330a(19) =220a(20) =328a(21) =1365a(22) =2730a(23) =2730a(24) =2793a(25) =8841a(26) =21420a(27) =28560a(28) =29172a(29) =62832