a(n) = A058162(n) / A000688(n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =60a(6) =120a(7) =640a(8) =3780a(9) =90720a(10) =362880a(11) =6652800a(12) =39916800a(13) =1037836800a(14) =10897286400a(15) =53137244160