Perfect powers using only prime digits and 1.

Terms

a(0) =1a(1) =25a(2) =27a(3) =121a(4) =125a(5) =225a(6) =512a(7) =1521a(8) =3721a(9) =7225a(10) =12321a(11) =13225a(12) =27225a(13) =35721a(14) =55225a(15) =57121a(16) =112225a(17) =133225a(18) =151321a(19) =172225a(20) =212521a(21) =235225a(22) =373321a(23) =511225a(24) =1125721a(25) =1177225a(26) =1357225a(27) =1525225a(28) =1535121a(29) =2217121