G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^5)^4.

Terms

a(0) =1a(1) =1a(2) =4a(3) =26a(4) =184a(5) =1451a(6) =12020a(7) =103734a(8) =921132a(9) =8364877a(10) =77317704a(11) =725029730a(12) =6880482816a(13) =65955731874a(14) =637703938860