Upper of a pair of adjacent perfect powers, both with exponents > 2.

Terms

a(0) =32a(1) =81a(2) =128a(3) =256a(4) =1024a(5) =1331a(6) =2197a(7) =50653a(8) =59319a(9) =195112a(10) =279936a(11) =456976a(12) =614656a(13) =3112136a(14) =6436343a(15) =22667121a(16) =25412184a(17) =38958219a(18) =62748517a(19) =96071912a(20) =131096512a(21) =418195493a(22) =506261573a(23) =741217625a(24) =796597983a(25) =1249243533a(26) =2136750625a(27) =2217373921a(28) =5554637011a(29) =5802888573