Numbers with an increasing number of nonprime divisors.

Terms

a(0) =1a(1) =4a(2) =8a(3) =12a(4) =24a(5) =36a(6) =48a(7) =60a(8) =72a(9) =120a(10) =180a(11) =240a(12) =360a(13) =720a(14) =840a(15) =1080a(16) =1260a(17) =1440a(18) =1680a(19) =2160a(20) =2520a(21) =4320a(22) =5040a(23) =7560a(24) =10080a(25) =15120a(26) =20160a(27) =25200a(28) =27720a(29) =30240