Palindromic mountain primes.

Terms

a(0) =131a(1) =151a(2) =181a(3) =191a(4) =12421a(5) =12721a(6) =12821a(7) =13831a(8) =13931a(9) =14741a(10) =17971a(11) =1235321a(12) =1245421a(13) =1257521a(14) =1268621a(15) =1278721a(16) =1456541a(17) =1469641a(18) =1489841a(19) =1579751a(20) =1589851a(21) =123484321a(22) =123494321a(23) =123575321a(24) =136797631a(25) =167898761a(26) =12345854321