Highly powerful numbers that are perfect powers.

Terms

a(0) =1a(1) =4a(2) =8a(3) =16a(4) =32a(5) =64a(6) =128a(7) =144a(8) =216a(9) =1296a(10) =1728a(11) =5184a(12) =7776a(13) =20736a(14) =129600a(15) =216000a(16) =518400a(17) =12960000a(18) =46656000a(19) =116640000a(20) =635040000a(21) =16003008000a(22) =280052640000