A034704 Largest number that can be made using only the digits of n, exponentiation and concatenation.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 21, 31, 41, 51, 61, 71, 81, 91, 20, 21, 22, 32, 42, 52, 64, 128, 256, 512, 30, 31, 32, 33, 81, 243, 729, 2187, 6561, 19683, 40, 41, 42, 81, 256, 1024, 4096, 16384, 65536, 262144, 50, 51, 52, 243, 1024, 3125, 15625, 78125