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

Terms

a(0) =1a(1) =0a(2) =1a(3) =-2a(4) =2a(5) =-6a(6) =3a(7) =-16a(8) =17a(9) =-34a(10) =47a(11) =-78a(12) =153a(13) =-178a(14) =373a(15) =-530a(16) =954a(17) =-1410a(18) =2280a(19) =-3896a(20) =5908a(21) =-9988a(22) =15170a(23) =-25908a(24) =40659a(25) =-65136a(26) =105967a(27) =-169056a(28) =276483a(29) =-435624