Palindromic primes using only (decimal) square digits 0,1,4,9.

Terms

a(0) =11a(1) =101a(2) =191a(3) =919a(4) =11411a(5) =19991a(6) =91019a(7) =94049a(8) =94949a(9) =1114111a(10) =1190911a(11) =1409041a(12) =1411141a(13) =1444441a(14) =1490941a(15) =1909091a(16) =1941491a(17) =9049409a(18) =9091909a(19) =9109019a(20) =9110119a(21) =9149419a(22) =9199919a(23) =9400049a(24) =9414149a(25) =9419149a(26) =9440449a(27) =9919199