G.f. satisfies: A(x) = 1 + x/A(-x*A(x)^4).

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =13a(5) =62a(6) =297a(7) =1523a(8) =8091a(9) =43243a(10) =234347a(11) =1267141a(12) =6814076a(13) =36368431a(14) =192079140a(15) =1006805203a(16) =5262612068a(17) =27656507707a(18) =147973596219a(19) =815825605806