Primes that remain prime through 2 iterations of function f(x) = 10x + 9.

Terms

a(0) =5a(1) =13a(2) =19a(3) =23a(4) =47a(5) =61a(6) =103a(7) =127a(8) =139a(9) =233a(10) =257a(11) =293a(12) =331a(13) =433a(14) =463a(15) =491a(16) =499a(17) =547a(18) =593a(19) =701a(20) =859a(21) =967a(22) =1009a(23) =1013a(24) =1049a(25) =1223a(26) =1321a(27) =1399a(28) =1493a(29) =1567