a(n) = A000265(A263931(n)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =9a(6) =3a(7) =3a(8) =45a(9) =5a(10) =1a(11) =21a(12) =7a(13) =175a(14) =675a(15) =45a(16) =45a(17) =1485a(18) =5775a(19) =5775a(20) =45045a(21) =2145a(22) =195a(23) =8775a(24) =2925a(25) =5733a(26) =22491a(27) =833a(28) =6545a(29) =373065