a(n) is the smallest number m with exactly n divisors whose last digit equals the last digit of m.

Terms

a(0) =1a(1) =11a(2) =40a(3) =60a(4) =160a(5) =120a(6) =640a(7) =240a(8) =360a(9) =480a(10) =8064a(11) =600a(12) =18144a(13) =1920a(14) =1440a(15) =1200a(16) =72576a(17) =1800a(18) =52416a(19) =2400a(20) =5760a(21) =30720a(22) =183456a(23) =3600a(24) =12960a(25) =122880a(26) =9000a(27) =9600a(28) =602784a(29) =7200