G.f. A(x) satisfies: A(x) = 1 + x*A(x)^2 - x^2/A(x)^2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =11a(5) =41a(6) =110a(7) =393a(8) =1180a(9) =4199a(10) =13538a(11) =48353a(12) =163130a(13) =585790a(14) =2035789a(15) =7353701a(16) =26078670a(17) =94767692a(18) =340963400a(19) =1246208999a(20) =4531981344a(21) =16653522634a(22) =61062317840a(23) =225484886305a(24) =832165390554