Powerful(1) numbers (A001694) whose digit reversal is a semiprime (A001358).

Terms

a(0) =4a(1) =9a(2) =49a(3) =64a(4) =121a(5) =169a(6) =289a(7) =400a(8) =512a(9) =625a(10) =900a(11) =961a(12) =968a(13) =1156a(14) =1225a(15) =1568a(16) =1849a(17) =2048a(18) =2401a(19) =2888a(20) =3125a(21) =3136a(22) =3364a(23) =3481a(24) =3721a(25) =4000a(26) =4900a(27) =4913a(28) =5041a(29) =5329