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

Terms

a(0) =1a(1) =1a(2) =7a(3) =31a(4) =273a(5) =1697a(6) =16471a(7) =116159a(8) =1186081a(9) =8928193a(10) =94017703a(11) =736522975a(12) =7917810225a(13) =63722594657a(14) =695248655095