Proper powers of primorial numbers.

Terms

a(0) =4a(1) =8a(2) =16a(3) =32a(4) =36a(5) =64a(6) =128a(7) =216a(8) =256a(9) =512a(10) =900a(11) =1024a(12) =1296a(13) =2048a(14) =4096a(15) =7776a(16) =8192a(17) =16384a(18) =27000a(19) =32768a(20) =44100a(21) =46656a(22) =65536a(23) =131072a(24) =262144a(25) =279936a(26) =524288a(27) =810000a(28) =1048576a(29) =1679616