Primes that remain prime through 4 iterations of function f(x) = 2x + 5.

Terms

a(0) =13a(1) =31a(2) =181a(3) =541a(4) =661a(5) =1087a(6) =1861a(7) =2179a(8) =2719a(9) =3727a(10) =7459a(11) =8089a(12) =8707a(13) =9109a(14) =10639a(15) =17341a(16) =19333a(17) =22501a(18) =23293a(19) =29287a(20) =32797a(21) =39847a(22) =40387a(23) =42703a(24) =46591a(25) =51613a(26) =53101a(27) =56149a(28) =56809a(29) =57829