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

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =9a(5) =55a(6) =117a(7) =775a(8) =1785a(9) =12350a(10) =29799a(11) =211876a(12) =527085a(13) =3818430a(14) =9706503a(15) =71282640a(16) =184138713a(17) =1366368375a(18) =3573805950a(19) =26735839650a(20) =70625252863a(21) =531838637759