Primes that remain prime through 3 iterations of function f(x) = 9x + 4.

Terms

a(0) =3a(1) =31a(2) =37a(3) =41a(4) =107a(5) =421a(6) =773a(7) =967a(8) =1451a(9) =1567a(10) =1571a(11) =1637a(12) =1973a(13) =3011a(14) =3793a(15) =4111a(16) =4217a(17) =4703a(18) =5783a(19) =6961a(20) =7331a(21) =8443a(22) =8627a(23) =9323a(24) =10733a(25) =12071a(26) =12413a(27) =12721a(28) =12967a(29) =13523