G.f.: Sum_{k>=0} A000041(k)^2 * x^k / Sum_{k>=0} A000009(k)^2 * x^k.

Terms

a(0) =1a(1) =0a(2) =3a(3) =2a(4) =16a(5) =10a(6) =59a(7) =32a(8) =187a(9) =90a(10) =519a(11) =152a(12) =1439a(13) =164a(14) =3525a(15) =-246a(16) =8904a(17) =-2500a(18) =21748a(19) =-10836a(20) =53918a(21) =-36508a(22) =131424a(23) =-115266a(24) =328703a(25) =-336608a(26) =812615a(27) =-957464a(28) =2046225a(29) =-2634166