a(n) is the largest number j whose n-th power has exactly j divisors.

Terms

a(0) =1a(1) =2a(2) =3a(3) =40a(4) =45a(5) =1a(6) =7a(7) =225a(8) =153a(9) =640a(10) =4851a(11) =6348a(12) =325a(13) =19474560a(14) =1a(15) =976a(16) =18513a(17) =1225a(18) =19a(19) =107747640000a(20) =81a(21) =1a(22) =23a(23) =245790720a(24) =49a(25) =2601a(26) =2133a(27) =3025a(28) =94221a(29) =56241820800