a(n) is the smallest number k with exactly n divisors in A033075.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =18a(5) =12a(6) =24a(7) =60a(8) =120a(9) =168a(10) =360a(11) =1080a(12) =840a(13) =3360a(14) =2520a(15) =7560a(16) =15120a(17) =30240a(18) =84840a(19) =196560a(20) =339360a(21) =254520a(22) =1102920a(23) =763560a(24) =1527120a(25) =4581360a(26) =3054240a(27) =9162720a(28) =9926280a(29) =19852560