G.f. satisfies: A(x - A(x) + A(x)^2) = x^4.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =36a(6) =112a(7) =361a(8) =1186a(9) =3974a(10) =13524a(11) =46612a(12) =162384a(13) =570880a(14) =2022800a(15) =7216480a(16) =25900036a(17) =93449752a(18) =338772408a(19) =1233326352a(20) =4507204720a(21) =16528765376a(22) =60805491392a(23) =224335046602a(24) =829851744732