Largely composite numbers (A067128) with a unique number of divisors.

Terms

a(0) =1a(1) =4a(2) =36a(3) =48a(4) =180a(5) =720a(6) =5040a(7) =20160a(8) =25200a(9) =45360a(10) =50400a(11) =498960a(12) =665280a(13) =3603600a(14) =6486480a(15) =7207200a(16) =8648640a(17) =14414400a(18) =32432400a(19) =110270160a(20) =698377680a(21) =2095133040a(22) =2205403200a(23) =41902660800a(24) =73329656400a(25) =146659312800a(26) =240940299600a(27) =293318625600a(28) =963761198400