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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =3a(6) =3a(7) =1a(8) =4a(9) =24a(10) =60a(11) =80a(12) =82a(13) =222a(14) =796a(15) =1848a(16) =2912a(17) =4452a(18) =11088a(19) =31592a(20) =70467a(21) =125437a(22) =231105a(23) =551775a(24) =1399069a(25) =3068219a(26) =5942937a(27) =12017739a(28) =27966515a(29) =66675777