(1/n)*A204991(n).

Terms

a(0) =2a(1) =1a(2) =2a(3) =1a(4) =6a(5) =1a(6) =2a(7) =1a(8) =14a(9) =3a(10) =186a(11) =1a(12) =630a(13) =1a(14) =2a(15) =1a(16) =30a(17) =7a(18) =27594a(19) =3a(20) =6a(21) =93a(22) =178a(23) =1a(24) =83886a(25) =315a(26) =19418a(27) =1a(28) =18512790a(29) =1