G.f. A(x) satisfies A(x) = 1 + x/(1+x^2)^3 * A(x)^2.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =2a(5) =3a(6) =6a(7) =14a(8) =34a(9) =83a(10) =204a(11) =505a(12) =1258a(13) =3152a(14) =7940a(15) =20100a(16) =51114a(17) =130525a(18) =334590a(19) =860728a(20) =2221432a(21) =5750503a(22) =14927470a(23) =38849487a(24) =101349738a(25) =264987476a(26) =694268316a(27) =1822504484a(28) =4792857868a(29) =12625700121