Semiprimes whose prime factors, when concatenated, yield a palindrome.

Terms

a(0) =4a(1) =9a(2) =25a(3) =39a(4) =49a(5) =69a(6) =119a(7) =121a(8) =129a(9) =159a(10) =219a(11) =249a(12) =259a(13) =329a(14) =339a(15) =403a(16) =469a(17) =669a(18) =679a(19) =1207a(20) =1329a(21) =1589a(22) =1703a(23) =2319a(24) =2321a(25) =2359a(26) =2649a(27) =2701a(28) =3039a(29) =3421