a(n) = A086323(n)/n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =6a(5) =6a(6) =18a(7) =20a(8) =50a(9) =74a(10) =186a(11) =216a(12) =630a(13) =916a(14) =2002a(15) =3040a(16) =7710a(17) =10806a(18) =27594a(19) =40642a(20) =94658a(21) =158492a(22) =364722a(23) =516682a(24) =1333926a(25) =2180772a(26) =4770374a(27) =7845774a(28) =18512790a(29) =28706044