Palindromic primes that yield a prime when sandwiched between two 9's.

Terms

a(0) =2a(1) =101a(2) =313a(3) =373a(4) =757a(5) =787a(6) =10301a(7) =12721a(8) =12821a(9) =17471a(10) =17971a(11) =19991a(12) =32423a(13) =35153a(14) =35753a(15) =37573a(16) =72727a(17) =73237a(18) =77977a(19) =78787a(20) =78887a(21) =90709a(22) =93139a(23) =93239a(24) =97879a(25) =1035301a(26) =1117111a(27) =1120211a(28) =1129211a(29) =1134311